JP6229160B2 - Washing machine - Google Patents

Description

  The present invention relates to a washing machine for storing clothes, having a drum having a vertical or horizontal rotating shaft, and stopping while applying a brake.

2. Description of the Related Art Conventionally, an inverter device used in a washing machine is detected by a rotor position detecting means of a motor, and the rotation of the motor is detected by a motor rotation detecting means or a counter electromotive force detecting means. Or when the rotation of the motor is detected by the back electromotive force detection means, a short circuit brake is performed. (For example, refer to Patent Document 1).
In addition, a rotor position detection circuit is provided in the motor, a trigger switch for instructing ON / OFF of the motor by an operator's trigger operation is provided, and the number of rotations during braking is detected by the rotor position detection circuit. When the engine speed becomes equal to or less than a predetermined number of revolutions, there is a method for calculating a time for ending the brake operation and releasing the brake operation after the time elapses (for example, see Patent Document 2).

 In addition, there is also provided a stop determination means for determining the motor rotation stop when the winding of the motor is short-circuited for three phases or more and the winding current detected by the current detection means in that state coincides with three or more phases. Yes (see, for example, Patent Document 3).

  FIG. 10 shows a conventional washing machine described in Patent Document 1. In FIG. As shown in FIG. 10, the AC power source 1, the rectifier circuit 2, the inverter circuit 3, the motor 4, the Hall IC, and the like, and rotor position detection means 5, 6, 7 that detect the rotor position of the motor 4, the motor 4. The back electromotive force detecting means 8 for detecting the back electromotive force of the rotor, the rotor position detecting means 5, 6, 7 or the back electromotive force detecting means 8 is used as a motor rotation detecting means for detecting rotation, and the control means 10 is When the motor rotation detecting means detects that the motor is rotating other than when the motor 4 is driven, all the lower arm transistors of the inverter circuit 3 are turned on through the inverter driving circuit 11, and the motor 4 performs short-circuit braking. The stop of the motor 4 is determined from the output of the motor rotation detection means by both the rotor position detection means 5, 6, 7 and the back electromotive force detection means 8.

FIG. 11 shows a circuit diagram of a conventional apparatus described in Patent Document 2. In FIG.
As shown in FIG. 11, the motor 16 is supplied with a three-phase current from the 14.4 V battery pack 17 through the inverter circuit unit 18, and the Hall ICs 20, 21, and 22 are controlled according to the rotation of the motor 16. Output signals sequentially.

  The control unit 23 is connected to a switch trigger 24 and a forward / reverse switching lever 25, and signals from the Hall ICs 20, 21, 22 are input through the rotor position detection circuit 27 and further input from the rotation amount detection circuit 28. The

  The control unit 23 further sets the rotation direction from the current detection circuit 31 for detecting the current of the inverter circuit FIG. 18, the switch operation detection circuit 32 and the applied voltage setting circuit 33 for receiving the signal of the switch trigger 24, and the forward / reverse switching lever 25. A signal is taken in through the circuit 34, and the control unit 23 turns on the three switching elements on the negative power source side in the inverter circuit unit 18 and turns off the three switching elements on the positive power source side, thereby By short-circuiting the three-phase windings, a path through which current during braking flows is formed, and braking operation by short-circuit braking is performed.

FIG. 12 shows an operation waveform diagram at the time of braking operation of the conventional device described in Patent Document 2. In FIG.

  Since the edge from the Hall ICs 20, 21, and 22 occurs every 30 degrees of rotation of the motor 16 during the brake operation, the motor rotation number can be calculated backward from the time interval. At time t1 when the time interval gradually increases and reaches the predetermined speed Nth, the time Tc is determined from the magnitude of the speed change, and the brake is released after Tc time, so that the brake is applied at t2 when the rotation becomes almost zero. Is released, and a driver drill with good responsiveness to subsequent user operations is realized.

FIG. 13 shows a circuit diagram of a conventional device described in Patent Document 3. As shown in FIG.
The inverter circuit 41 that supplies a current to the winding of the motor 40 includes switching elements 42 to 47, and the control unit 48 controls on / off.

  In order to detect the current flowing in the winding of the motor 40, the shunt resistors 50 and 51, and the amplification / bias circuits 52 and 53 including the operational amplifier are provided, and the output signals are input to the control unit 48, and the U phase and the V phase Current value is detected, and the W phase is also calculated from the U phase and V phase currents, and all three phase currents are detected.

  Further, an overcurrent detection signal from the overcurrent detection unit 56 is also input to the control unit 48 via the diodes 54 and 55 at the time of overcurrent.

FIG. 14 shows a flowchart at the time of start-up. From the start start 60 to the short circuit 61, the winding of the motor 40 is short-circuited for all three phases.
In the subsequent rotor stop 62, it is determined whether or not the winding currents detected by the current detection means match three or more phases. If they match, it is determined that the motor 40 has stopped.
Thereafter, the process proceeds to positioning 63, forced commutation 64, and steady operation 65, and shifts from startup to steady operation.

FIG. 15 shows a winding current waveform diagram during short-circuit braking when the motor is rotating.
During rotation, the instantaneous value of the current for two phases of the current of three phases may match, but the value for three phases does not match, and stops when the current values for three phases match It will be judged.

  Although not shown, there is also described a configuration in which a single-phase current detection value is referred to twice or more at intervals shorter than one cycle of the current waveform and is determined to be stopped when they match.

JP 2003-275494 A JP 2011-5588 A Japanese Patent Laid-Open No. 2005-6453

  However, in the first conventional configuration, whether or not the motor 4 is stopped is determined by the output of the rotor position detecting means 5, 6, 7 or the counter electromotive force detecting means 8 constituting the motor rotation detecting means. Therefore, the cost is high.

In particular, although it is different from the configuration of Patent Document 1, it is called position sensorless, and in the case of using a configuration in which the rotor position detection means 5, 6, 7 are not required for driving, it is determined whether or not it has been stopped by a short-circuit brake. Therefore, it is necessary to provide the rotor position detecting means only for performing the above-described process, resulting in an increase in cost.

  Further, the back electromotive force detection means 8 is not necessarily required as a position sensor-less configuration, so it is also an element of cost increase.

  Further, the second conventional configuration is a configuration in which the position detection of the rotation of the motor by the Hall IC and the rotor position detection circuit is provided, and there is a problem that the cost becomes high.

  In addition, in the third conventional configuration, when noise is detected in the current detection value, the current detection values for the three phases may coincide with each other even during rotation. If a fixed signal voltage such as 0V or 5V is input to the control unit due to a failure in the amplifier / bias circuit, a condition for determining whether to stop is satisfied. When the drum lid can be opened, unsafeness occurs.

  The present invention solves the first to third conventional problems, and provides an electric washing machine capable of ensuring safety by determining stoppage with a short-circuit brake without providing a position detector such as a Hall IC. The purpose is to do.

In order to solve the conventional problems, a washing machine of the present invention, the lid for opening and closing a drum for accommodating the clothing, an electric motor for driving the drum has a permanent magnet and a winding, an opening of the drum A lid locking means for locking the lid, a plurality of switching elements, an inverter circuit for supplying current to the electric motor, and a control means for controlling on / off of the switching elements, the control means, Current detecting means for detecting the current; and speed calculating means for receiving the output of the current detecting means to calculate the speed of the electric motor, and the control means inputs the electric motor during the braking period of the drum. A washing machine that controls the switching element so as to keep the voltage substantially zero, and sets the lid locking means in a state in which a user can open the lid after the speed becomes a predetermined value or less. , Serial control means before the braking period, and has a voltage reduction period for controlling the switching element to reduce the absolute value of the input voltage of the motor.

  This allows a user to open the lid with a sufficiently high safety while having a simple and low-cost configuration that does not have a position sensor such as a Hall IC, and calculates a physical quantity called speed. Therefore, it is possible to adjust the responsiveness by effectively using the existence of speed continuity due to the moment of inertia. Even when it is fixed to a constant value regardless of the current value, it is possible to realize a highly safe washing machine in which erroneous stop determination is not performed.

  The washing machine of the present invention can appropriately determine the stop of the electric motor without depending on a position detector such as a Hall IC.

Block diagram of the inverter device of the first embodiment FIG. 2 is a block diagram showing a detailed configuration in central control unit 135 of the inverter device in the first embodiment. Waveform diagram in case of short circuit brake by B99RQ of inverter device in embodiment 1 Operation waveform diagram before and after drum 106 of inverter device in Embodiment 1 stops Waveform diagram of operation waveform diagram in case of entering short-circuit braking period by brake request signal B4RQ from sequence generating means 167 of inverter device in embodiment 1 Operation waveform diagram centering on speed calculation means 120 before and after drum 106 stops after moving to the short-circuit braking period by B4RQ of the inverter device in the first embodiment. Sectional drawing of the drum-type washing machine provided with the inverter apparatus in Embodiment 1 In Embodiment 1, the flowchart figure immediately after the power supply of an inverter apparatus is turned on The block diagram which shows the principal part of the inverter apparatus in Embodiment 2. Conventional washing machine described in Patent Document 1 Circuit diagram of a conventional device described in Patent Document 2 Operation waveform diagram at the time of brake operation of the conventional device described in Patent Document 2 Circuit diagram of a conventional device described in Patent Document 3 Flow chart at the time of starting the conventional apparatus described in Patent Document 3 Current waveform diagram of conventional device described in Patent Document 3

A first aspect of the present invention is a drum for accommodating the clothing, an electric motor for driving the drum has a permanent magnet and a winding, and a lid for opening and closing the opening of the drum, and a lid locking means for locking said lid An inverter circuit that has a plurality of switching elements and supplies current to the motor; and a control unit that controls on / off of the switching elements, the control unit including a current detection unit that detects the current; Speed calculation means for calculating the speed of the electric motor in response to the output of the current detection means, and the control means keeps the input voltage of the electric motor at substantially zero during the braking period of the drum. And the lid lock means is in a state in which a user can open the lid after the speed becomes equal to or less than a predetermined value , the control means before the braking period. In addition, By having a voltage reduction period for controlling the switching element to reduce the absolute value of the input voltage of the serial motor, while having a simple configuration, and that the stop of the electric motor can be appropriately determined.
Further, generation of a transient overcurrent to the electric motor can be suppressed, and sufficient reliability can be realized even if the current capacity of the switching element is small.

  In the second invention, in particular, the electric motor of the first invention has a three-phase winding, the current detection means detects a current of two or more of the three phases, and the speed calculation means By calculating the speed based on the current value of two or more of the three phases, the speed synchronized with the rotation of the motor can be calculated. Thus, it is possible to realize a washing machine that can be calculated with extremely high stability and has high stability based on the determination of stoppage.

  According to a third aspect of the invention, in particular, the electric motor of the second aspect of the invention has a three-phase winding, and a variable frequency oscillation means for outputting the phase of the permanent magnet including a time integral value of speed, a phase error detection means, Coordinate conversion means, wherein the current detection means detects a current of two or more of three phases, and the coordinate conversion means uses the phase to change the output of the current detection means from stationary coordinates to rotational coordinates. The speed calculation means receives the current value signal at the rotation coordinates and calculates the speed, so that the speed synchronized with the rotation of the motor can be reliably calculated. Therefore, the low-speed state immediately before stopping can be calculated with extremely high stability, and a washing machine with high stability based on the determination of stop can be realized.

According to a fourth aspect of the present invention, in particular, after the power is turned on according to any one of the first to third aspects of the invention, the lid lock means has the braking period before the user can open the lid. As a result, safety can be ensured even when inertial rotation due to the previous operation remains at the time of power-on.

In the fifth aspect of the invention, in particular, since the electric motor of any one of the first to fourth aspects is a sensorless system that does not have a position detector, it is possible to appropriately determine whether the electric motor has stopped, and low-cost washing. Can provide a machine.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a block diagram of an inverter device according to the first embodiment of the present invention.

  In FIG. 1, an electric motor 109 which has permanent magnets 100 and 101 and three-phase windings 102, 103 and 104, and which drives a drum 106 for storing clothing 105 through a pulley 107 and a belt 108, and six stones. Switching elements 111, 112, 113, 114, 115, 116, an inverter circuit 117 that supplies AC currents Iu, Iv, Iw to the electric motor 109, and switching elements 111, 112, 113, 114, 115, 116 The control means 118 has on / off control, and the control means 118 detects the alternating currents Iu, Iv, and Iw, the current detection means 119, and the speed calculation means 120 that receives the output of the current detection means 119 and calculates the speed of the electric motor 109. In this embodiment, the current detection means 119 converts the current of each of the three phases into a voltage. The speed calculation means 120 includes an A / D converter 124 that performs A / D conversion during the ON period of the shunt resistors 121, 122, 123 to be switched and the switching elements 114, 115, 116 on the low potential side. The phase error detecting means 126 and the variable frequency oscillating means 127 are provided with an amplifier 128 and an integrator 129.

  In the present embodiment, a configuration called a three shunt using three resistance shunt resistors 121, 122, 123 corresponding to each of the three phases is used as the current detection means 119, and a switching element on the low potential side is used. Is detected from the voltage generated across each shunt resistor during the period in which 114, 115, and 116 are on, but each shunt resistor is called a single shunt, and each of the three phases is detected from the detection timing. A configuration in which the current values Iu, Iv, and Iw are separated, or two to three current sensors that can be detected from a direct current component such as DCCT may be used.

  Here, the amplifier 128 has two gain components, that is, a P component (proportional component) and an I component (time integration component) with respect to the input, and the input to the amplifier 128, that is, the phase error detection means 126. Output as a control loop that constantly becomes zero.

  Further, the control means 118 has a low speed judgment means 130 for judging that the output signal ω of the variable frequency oscillation means 127 has become a sufficiently low speed, and comprises a threshold generator 131 and a comparison means 132. It has become.

  Further, the control unit 118 includes a central control unit 135, generates signals for controlling the inverter circuit 117, receives output signals Iua, Iva, Iwa signals from the current detection unit 119, and receives a signal ω from the speed calculation unit 120. , Θ, and various signal processes such as reception of the J signal of the low speed determination means 130 are all performed digitally.

The PWM circuit 136 receives the Duty signal from the central control unit 135 and outputs a signal B obtained by performing pulse width modulation (PWM) with a triangular wave having a period of 64 microseconds on the Duty signal. 135 signals S1 to S6 give the gate signals of the switching elements 111, 112, 113, 114, 115, 116 via the switching means 137 and the drive circuit 138 provided between the inverter circuit 117 and the inverter circuit 117. However, when the K signal of the central control unit 135 is high, the switching unit 137 is in the state shown in FIG. 1 and S1 to S6 are adopted, whereas the K signal is low. If it is, each switch in the switching means 137 is connected to the lower side.

  The inverter circuit 117 is supplied with a DC voltage VDC from a DC power supply 144 constituted by an AC power supply 141 of AC 230 V 50 Hz, a full-wave rectifier 142 and a capacitor 143, and an output of a DC voltage detection circuit 148 constituted by resistors 146 and 147. A is input to the central control unit 135 as an analog voltage signal, and is also processed as a digital value subjected to A / D conversion inside the central control unit 135.

  FIG. 2 is a block diagram showing a detailed configuration in the central control unit 135 of the inverter device according to the first embodiment of the present invention.

  As an actual part for realizing the central control unit 135, a one-chip type microcomputer or the like is used. However, one microcomputer including the part outside the central control unit 135 in FIG. May be realized by processing the software, or conversely, the configuration in the central control unit 135 may be realized by hardware, or may be realized as a single chip or a multi-chip part, or a DSP. It is also possible to use various processors called as components.

  In FIG. 2, using the signals Iua, Iva, Iwa corresponding to the three-phase currents Iu, Iv, Iw and the calculated phase θ signal, conversion to Id and Iq using Equation 1, that is, from stationary coordinates to rotating coordinates Of the first coordinate conversion means 150 that performs the conversion to and outputs, the subtraction means 151 that calculates the error between the set values Idr and Id, the subtraction means 152 that calculates the error between the set values Iqr and Iq, and the subtraction means 151 and 152 Error amplifying means 153 and 154 for applying a gain of PI (proportional and integral) to the output are provided, and their outputs Vd1 and Vq1 are converted to eq. A second coordinate conversion means 158 is provided for use to convert the voltage command values Vu, Vv, and Vw into three-phase voltage command values. In the PWM means 159, a three-phase voltage command for the A signal is provided. In proportion, by the action of carrier wave of the triangular wave of 64us period, the instantaneous value comparison between the carrier wave, and it is denoted by the dead time, and configured to generate a vertical drive signal S1 to S6.

In the present embodiment, the current detection means 119 is configured to detect all three phases of current, but the current of two or more phases in the three-phase windings 102, 103, 104 of the electric motor 109 is detected. If detected, the remaining one phase can be calculated according to Kirchhoff's law, so only two phases may be detected.

  The present embodiment further includes a subtracting means 160 for calculating the difference between the speed set values ωr and ω, an error amplifying means 161 for applying a gain of PI (proportional, integral) to the output of the subtracting means 160, a calculated speed. Idr setting means 162 that determines Idr from ω, short-circuit brake control means 163, abnormality detection means 165, delay means 166 that outputs a Z signal with a delay time of 0.3 seconds from the J signal, set speed ωr when the motor 109 is driven Sequence generator 167 for generating the brake request signal B4RQ, and a voltage command throttle 168 for receiving the B4RQ signal, inputting Vd1 and Vq1 at the start of the transition to the short-circuit brake, and outputting a value approaching zero. It has been.

  Since the sequence control unit 167 operates as an electric washing machine, various signals with external components (stop button signal Sstop, water supply valve signal Skb, drain valve signal Shb, lid lock signal Srk, lid closure signal Scl, etc.) Various signals relating to the operation of the electric motor 109 are also transmitted and received.

  The short-circuit current determination means 170 sets the Cl signal to high when any of the instantaneous values of the current signals Iua, Iva, Iwa for three phases in the short-circuit state exceeds 1.7 A, and the instantaneous value When all of the absolute values are less than 0.6 A, the Cs signal is set to high.

  The Idr setting means 162 outputs 0A as Idr when the ω value is 400 r / min or less in terms of the speed of the drum 106, and sets Idr <0A when it exceeds 400 r / min in terms of the speed of the drum 106. However, as the absolute value is gradually increased as ω is increased, Idr = −5 A is obtained at 1200 r / min in terms of the speed of the drum 106, and weak field control at high speed is applied. It has become.

  The short-circuit brake control unit 163 performs control when an abnormality occurs in the electric washing machine and when the electric motor 109 is stopped in a braking state at the time of the operation break. If there is excessive vibration or the like, the input of the motor 109 is gradually short-circuited, that is, three-phase when the B99RQ signal from the abnormality detecting means 165 and the brake request signal B4RQ from the sequence generating means 167 are received. The gate control for the switching elements 111, 112, 113, 114, 115, 116 in the inverter circuit 117 is realized so that the voltage between the input terminals becomes substantially zero. In particular, in this embodiment, B99RQ is Both when receiving and when receiving B4RQ, it is a short-circuit brake state, Signal to the body specific inverter circuit 117 is assumed to have quite different.

  FIG. 3 is a waveform diagram in the case where a short-circuit brake is caused by B99RQ of the inverter device according to the first embodiment of the present invention, where (A) is a B99RQ signal, (A) is a K signal, and (C) is a Duty signal. It is.

  From the power running period, the internal signal BRQ of the central control unit 135 becomes high at time t1 and at the same time the K signal changes from high to low, but since the duty value is zero at this time, the switching elements 111, 112, 113, 114 , 115 and 116 move to an all-off period of 5 ms in which all of the IGBT portions are turned off.

  During the all-off period, when the electric motor 109 is at a low speed, the current is almost zero. However, when the electric motor 109 is at a high speed (the induced electromotive force is high), the switching elements 111, 112, 113 are used. , 114, 115, and 116, a regenerative current to the DC power source flows through the diode portion.

The on-time ratio (Duty) of the low potential side switching elements 114, 115, and 116 shown in (c) is the short-circuit time ratio, and following the all-off period, the short-circuit time ratio increases from T2 to T5 in which the duty increases. On the other hand, the high-potential side switching elements 111, 112, and 113 are kept off by the action of the switching unit 137.

  Thereafter, as time passes through T3 and T4, the gradient with respect to time, that is, the expansion rate of the short circuit time ratio (Duty) decreases with time, and decreases as the short circuit time ratio approaches 100%.

  From the viewpoint of the input voltage of the electric motor 109, the induced electromotive force generated by the rotation repeats positive / negative as an instantaneous value, but it is forced to be zero during the short circuit time, and the absolute value is suppressed. Become.

  Therefore, in the present embodiment, the short-circuiting time ratio expansion period from T2 to T5 is a voltage reduction period in which the switching elements 114, 115, and 116 are controlled so that the absolute value of the voltage decreases as the short-circuiting time increases.

  At T5, when the duty reaches 100%, the motor 109 causes the control means 118 to control the on / off of the low potential side switching elements 114, 115, and 116 in the inverter circuit 117, so that the input terminal UVW of the three-phase winding. After the short-circuit time ratio expansion period for expanding the short-circuit time ratio (Duty) for short-circuiting, the short-circuit time ratio Duty is kept at the maximum, that is, 100%, and has a short-circuit braking period for absorbing the kinetic energy of the load. Yes.

  When the duty becomes 100%, the voltage drop of the IGBT and the diode in the low potential side switching elements 114, 115, 116 and the voltage drop due to the wiring from the inverter circuit 117 to the motor 109 are the input of the motor 109. For example, about 2 to 3 V remains as a voltage, but such a voltage is in the range of substantially zero.

  In this way, by gradually increasing the duty, which is the short-circuit time ratio, it is possible to prevent a transient current jump in the process of moving to the short-circuit braking period, and to prevent overcurrent. The breakdown of each component and the overcurrent failure of the electric motor 109 can be prevented.

  In particular, in the present embodiment, since the expansion speed of the short circuit time ratio is gradually reduced, even if the speed condition of the electric motor 109 at the time of entering the short circuit braking period is varied over a wide range, Design of an enlargement speed of Duty near T2 to T3 under high speed conditions, and an enlargement speed of Duty near T4 to T5 under low speed conditions It becomes possible to cope with.

  In particular, from the aspect of suppressing overvoltage due to regeneration to the DC power supply 144 at high speed, the short-circuit time ratio (Duty) expansion speed at T3 to T5, which is the latter half of the short-circuit time ratio expansion period, is set under the medium-speed to low-speed conditions. By designing the transient current to rise within an allowable range, it can be minimized.

  And since the overcurrent of the line current when the electric motor 109 enters the short-circuit braking period under a wide range of speed conditions can be suppressed, the occurrence of overvoltage due to regeneration of the DC power supply 144 can be suppressed, and speed information is unnecessary. It is possible to cope with a low-cost configuration in which the motor 109 called sensorless does not have a position detection sensor and a speed detection sensor.

Furthermore, even in the case of an inverter device in which the rotation direction of the electric motor 109 is not one direction but is rotated to the right or to the left as in the case of an electric washing machine, the operation shifts to the short-circuit brake (short-circuit brake) period regardless of the phase order. Since control is possible, it becomes effective.

  FIG. 4 shows a short-circuit brake due to the B99RQ of the inverter device according to the first embodiment of the present invention. Further time elapses from the period shown in FIG. 3 and before and after the electric motor 109 and the load drum 106 are stopped. An operation waveform diagram is shown.

  4A shows the speed of the drum 106, FIG. 4B shows the current waveforms of Iu, Iv, and Iw, and FIG. 4C shows the Cs output signal of the short-circuit current determining means 170.

  The speed of the motor 109 that has entered the short-circuit braking state gradually decreases, and at the same time, the frequency of the line current decreases approximately in proportion to the speed, the amplitude of the line current also eventually decreases, and the speed becomes zero. Will converge to zero.

  In the present embodiment, the output of the current detection means 119 in the case of zero current is about 2.5V, which is almost the middle of the 5V power supply, but the switching elements 114, 115, 116 before the start of operation are off. The value in the state is stored and used as an offset value corresponding to zero current, and is handled by the absolute value of the line current of each phase.

  Regarding the time from when the short-circuit brake is entered to when the motor is stopped, the speed of the motor 109, the moment of inertia of the load, the inductance and resistance value of the motor 109, and the switching elements 114, 115, 116 being turned on when the short-circuit brake is entered. Since it depends on the voltage (VCE (SAT)) in the state and is not a fixed time, the current value, which is a physical phenomenon that appears due to a decrease in speed, is used in this embodiment, so that the speed is sufficiently low. It is assumed that the state where the speed has decreased is detected.

  Specifically, in the present embodiment, the Cs signal becomes high at the time Tja when all the absolute values of the instantaneous values of the three line currents Iu, Iv, and Iw are less than 0.6 A, and the drum 106 The speed is reduced to about 7 r / min.

  The short-circuit brake control means 163 receives the Cs signal that has become high, and stops when the short-circuit brake is continued from 7r / min. For example, when a delay time of 0.15 seconds elapses, the short-circuit brake control means 163 determines that it is stopped. In response to an instruction from the sequence generation unit 167, the process proceeds to the next step necessary for the electric washing machine.

  For the sake of completeness, the determination by the short-circuit current determination means 170 is configured to output Cs at a high level after confirming that the line current has sufficiently decreased again after Tja, or the line currents Iu, Iv, The Cs signal may be output at a high level when the absolute value of the instantaneous value of Iw is all below 0.6 A for a predetermined time or longer.

  As described above, it is possible to ensure safety by using a short-circuit brake and determining an appropriate stop from the current during that period, while having a low cost and simple configuration that does not use a position sensor or speed sensor. It will be possible.

  FIG. 5 is a waveform diagram of an operation waveform diagram when the short circuit braking period is entered by the brake request signal B4RQ from the sequence generation means 167 of the inverter device in the first embodiment of the present invention, and (A) shows the B4RQ signal. (A) shows the input values Vq (solid line) and Vd (broken line) values of the second coordinate conversion means 158, and (c) shows the calculated velocity ω (solid line) and the actual angular velocity (broken line).

  In the powering period before the time T1 when the B4RQ signal rises, the switching unit 156 contacts the lower contact, so that the outputs Vd1 and Vq1 of the error amplifying units 153 and 154 are connected to Vd and Vq, and Id and Iq Current control is functioning.

  At T1, when B4RQ becomes high, the voltage command restricting means 168 holds Vd1 and Vq1 inside, and after T1, the absolute value is decreased at a constant voltage change rate (dV / dt) with respect to time. The switching means 156 contacts the upper contact, and the signals from the voltage command restricting means 168 are used as Vd and Vq.

  In the example shown in FIG. 5, at T1, Vq1 is positive but Vd1 is a negative value. Therefore, the voltage command throttle means 168 approaches zero by subtracting Vq from Vq1, and Vd1 With respect to, the operation becomes closer to zero by increasing from Vd1, and changes in the direction of decreasing the absolute value.

  FIG. 5 shows a case where the absolute value of Vd1 is smaller than the absolute value of Vq1, and the throttle operation by the voltage command throttle means 168 after T1 reduces the absolute value at a constant time ratio. Therefore, in (A), the absolute value of the slope after T1 becomes equal between Vd and Vq, Vd becomes zero at T2, and Vd and Vq become zero at T3. The absolute value of the voltage drops to almost zero, and the electric motor 109 enters a short-circuit braking period in which kinetic energy is absorbed.

  The input voltage of the electric motor 109 is determined by the voltages Vu, Vv, and Vw that are the outputs of the second coordinate conversion means 158. In the period from T1 to T3, the voltage is also seen as the line voltage. Since the switching elements 111, 112, 113, 114, 115, and 116 are controlled so as to decrease, the voltage reduction period is reached.

  In the present embodiment, Vd and Vq are not zero at the same time, but the voltage reduction periods T1 to T3 are performed within a relatively short time of about several tens of ms. Adverse effects due to the difference between the curve and the Vq curve do not appear remarkably, and it does not lead to the generation of overcurrent due to transient line current jumps, or the occurrence of overvoltage of DC voltage due to regenerative power to the DC power supply 144. It will not be.

  In the present embodiment, with respect to ω shown in (c), the output ω of the amplifier 128 is fixed to the calculated speed ω1 at the time T1 when the B4RQ signal starts only during the voltage reduction period, and the stability of feedback. Is to ensure.

  The curve of the change of Vd and Vq during the voltage reduction period may be other, for example, a curve whose slope is adjusted so that Vd and Vq are simultaneously zero. Further, the magnitude of the time change of Vd and Vq (the absolute value of the inclination) may be changed according to the speed of the electric motor 109 when entering the short-circuit braking period. The inclination is small at low speed and large at high speed. Then, it is possible to suppress the generation of overvoltage due to the regenerative current to the DC power supply at high speed as much as possible while suppressing the transient current jump (overcurrent) during the voltage reduction period at any speed.

  Alternatively, the slope a during the voltage reduction period may be changed, and the initial slope is large and the slope is small, so that it corresponds to a wide range of speeds.

In any case, when the B4RQ signal becomes high, the voltage command values Vd and Vq are reduced to zero with time, so the input of the motor 109 is gradually short-circuited, that is, between the three-phase input terminals. Switching element 1 in the inverter circuit 117 in a direction in which the voltage of
11, 112, 113, 114, 115, 116 has a voltage reduction period in which gate control is performed, and then enters a short-circuit braking period in which Vd and Vq are zero and the input voltage of the motor 109 is substantially zero. .

  However, even if the voltage command values Vd and Vq are both zero, the input voltage of the electric motor 109 may not be completely zero V. Especially when three-phase modulation is performed, the VDC Centering on half the potential, the potential rises and falls within the dead time depending on the instantaneous line currents Iu, Iv, and Iw of each phase, and the voltage drop due to the IGBT or diode is 2 to 3 V or less. However, there are also factors that occur.

  These voltages may be reduced by using a configuration called dead time compensation, but especially when applied to an electric washing machine, the carrier frequency is considerably high at about 10 kilohertz from the viewpoint of noise prevention. Although the input voltage of the electric motor 109 of about several volts may remain, these are in the category where the input voltage is substantially zero.

  FIG. 6 shows the speed calculation means 120 before and after the electric motor 109 and the drum 106 as a load stop after the time has passed after the short-circuit braking period is started by the B4RQ of the inverter device according to the first embodiment of the present invention. The operation waveform diagram centered is shown. (A) shows Iu, (B) shows ω, (C) shows θ, and (D) shows the waveform of the J signal.

  Since the motor currents Iu, Iv, and Iw flow considerably during the short-circuit braking period, in this embodiment, Iua corresponding to the U phase in the signal that has passed through the current detection means 119 is supplied to the phase error detection means 126. The signal corresponding to the phase difference between the captured U-phase current Iu waveform and the output θ of the variable frequency oscillation means 127 is generated.

  Specifically, a phase difference comparison from the zero point timing or multiplication of two input signals is used, and the output is a kind of phase locked loop (PLL) composed of a control loop by an amplifier 128 and an integrator 129. ) Is generated during the short-circuit braking period, θ is generated in synchronization with the phase of Iu, and the angular frequency ω is a value corresponding to the speed of the electric motor 109, that is, a calculated speed (or a calculated value of the angular speed). It will be.

  Thus, since the ω output of the amplifier 128 can be used as the speed during the short-circuit braking period, the J signal of the comparison means 132 is output at T1 when ω is lower than the value ωth of the threshold generator 131. Thus, in this embodiment, T1 is the time when the drum 106 speed is 35 r / min, and the J signal becomes high at ωth.

  When it is determined whether or not the low speed state close to the stop has been reached from only the instantaneous value of each line current of the electric motor 109, it tends to be easily affected by sudden noise, for example, it rotates at a considerably high speed. Even when there are many cases, the output values of the current detection means 119 for three phases often coincide with each other, and even when the current detection value of one phase is referenced twice or more at intervals shorter than one electrical angle cycle. The possibility of matching due to noise increases as the time increases, and it may be erroneously determined that the speed is sufficiently low.

  Also, even if the number of references is increased in order to prevent the influence of noise, the influence of noise cannot be effectively reduced in many cases. Conversely, even in a stopped state, the speed is sufficiently low due to the influence of noise. Problems such as taking a very long time to determine the state also occur.

On the other hand, in the present embodiment, since the determination is made with the physical quantity of the speed or the frequency corresponding one-to-one corresponding thereto, particularly in the case of a drum-type washing machine, the inertia moment of the drum 106 is 0.3 kg square meter. It is possible to effectively use the point at which the speed fluctuation (acceleration) is limited due to the presence of about a certain degree, and to use a low-pass element within a range in which the responsiveness of the ω value can be sufficiently realized. There is an effect that it is possible to suppress the influence of output noise to a very low level, and a highly reliable ω signal can be obtained until immediately before stopping.

  After the J signal enters the central control unit 135, the delay means 166 causes the Z signal to go high after a delay time of 0.3 seconds. This 0.3 second is the speed of the drum 106. 35 r / min, corresponding to the time required to stop by continuing the short-circuit brake.

  Regarding the Cl signal, any of the absolute values exceeds 1.7 A, and becomes high when there is sufficient amplitude to detect the frequency from the current. Therefore, by multiplying the Cl signal condition, Sufficient reliability is added to the speed detection.

  As described above, in the present embodiment, when short-circuit braking is performed by the B4RQ signal from the sequence generation unit 167, the speed calculation unit 120 is used, so that the current Iu or the like is somewhat temporary. Even in the case of noise, as long as the phase error detection means 126 is within a normal working range, the influence of noise is not affected at all, and the operation as a phase locked loop is not affected. Even if there is an instantaneous malfunction of the phase error detection means 126, the integral gain element in the amplifier 128 tends to suppress the influence as the speed calculation means 120, and it is possible to ensure safety by determining a reliable stop. Will be made.

If the input voltage of the electric motor 109 deviates from zero due to the above-described dead time, a regenerative current to the DC power supply 144 is generated in some cases, and a rise in VDC may be a problem due to charging of the capacitor 143. May be suppressed by dead time compensation.
Therefore, appropriate dead time compensation is effective from the viewpoint of preventing overvoltage of the VDC and calculating the speed of the electric motor 109 with accuracy as low as possible.

As described above, in the present embodiment, the control unit 118 switches the switching elements 111, 112, 113, and so on to keep the input voltage of the electric motor 109 substantially zero during the short-circuit braking period in which kinetic energy from the drum is absorbed. 114, 115, and 116 are controlled, and after the calculated speed ω becomes equal to or less than the predetermined value ωth, the stop is determined.
Accordingly, for example, the stop of the electric motor 109 can be appropriately determined while having a simple configuration without a position detector such as a Hall IC, and safety can be ensured.

  In the present embodiment, the Cs signal is not used for the stop determination at the time of the B4RQ signal. However, it may be used together, for example, the Cs signal again 0.3 seconds after the Z signal is generated. It is also possible to check the state and determine whether to stop.

  Also, in the unlikely event of a very rapid deceleration, etc., if the current becomes small and the Cl signal goes low before the determination of 35 r / min is made, the stop determination will not be made forever, and the inverter Although it is conceivable that the device will be closed, it is determined that it is stopped by using together with the Cs signal or using an appropriate timer, etc., and by determining the stop after sufficient time has passed, It is possible to proceed to the next sequence in a form that balances safety and convenience of the inverter device.

  FIG. 7 is a cross-sectional view of an inverter device generally called a drum type washing machine in the present embodiment.

  In FIG. 7, a drum 106 that houses clothing 105, a pulley 182, and an electric motor 109 that is driven to rotate via a belt 108 are provided, and an inverter circuit 117 that supplies a three-phase alternating current to the electric motor 109 is provided.

  The inverter circuit 117 is operated by a control signal for 6 stones from the control means 118, and corresponds to the B99RQ signal and B4RQ described in the first embodiment, respectively, as shown in FIG. After the voltage reduction period for the B99RQ signal and the voltage reduction period for the B4RQ shown in FIG.

  Regarding the determination of the stop, safety is ensured by the determination of the stop during the short-circuit braking period in each of the configurations of B99RQ and B4RQ described in the first embodiment.

  In the present embodiment, the drum 106 rotates inside a resin cylinder 190, and opens and closes the water supply valve 193 and the drain valve 194 by the Skb signal and the Shb signal from the control means 118. As a result, water is supplied and drained into the receiving tube 190, and washing and dehydration are performed together with a separately supplied detergent.

  Here, a lid 196 that can be opened and closed is provided in front of the drum 106, and a lid handle 197 is provided for the user to open and close the lid 196. When the drum 106 rotates during washing and dehydration, the drum 106 rotates. The lid 196 is closed to ensure the safety of the user and prevent water from splashing.

  A state in which the lid 196 is opened by operating the handle 197 is indicated by a broken line.

  In the present embodiment, the lid 196 opens and closes around a hinge portion connected to the main body, but it has a sliding door configuration, a folding configuration, a shutter configuration, and a removable configuration. It doesn't matter.

  The lid lock means 200 holds the lid 196 in a closed state, and includes a solenoid 201, a plunger 202, a spring 203, and a lock control circuit 204, and the solenoid 201 is not energized. In this state, since the lid 196 is locked, the lid 196 cannot be opened even if the user pulls the handle 197 or performs any other operation.

  The lock control circuit 204 energizes the solenoid 201 in response to the Srk signal from the control means 118, and when the lock is released, the user can pull the handle 197 to open the lid 196.

  The lid detection switch 206 detects the open / closed state of the lid 196. The lid detection switch 206 transmits an open / close detection signal Scl to the control means 118. When the lid 196 is opened, Scl becomes low and ensures safety. Therefore, as a signal to the inverter circuit 117, the alternating current is not supplied to the electric motor 109, and the operation of rotating the drum 106 is not performed.

In this state, a direct current may be supplied to the electric motor 109, and sufficient safety can be ensured by ensuring that the drum 106 is fixed in the rotational direction more reliably.
When the dehydration operation or the like is finished, after the control means 118 determines that the operation is stopped, an Srk signal is sent, and the lid lock means 200 is released from the locked state by energizing the solenoid 201. The user can open the lid 196.

  As for the case where the dehydration operation is stopped, in addition to the case where the predetermined dehydration time has been reached, when the user operates the stop button 208 and a stop signal is generated, an abnormality such as an overload has occurred in the inverter circuit 117. Even when an abnormal signal is generated in the control means 118, the motor 109 is braked, and when the drum 106 is stopped, it is determined that the control means 118 is stopped by the B4RQ signal, and the lid lock is performed. The means 200 is unlocked, and the user pulls the handle 197 so that the lid 196 can be opened, so that safety is ensured.

  FIG. 8 shows a flowchart immediately after the power of the inverter device is turned on in the present embodiment.

  In FIG. 8, when the microcomputer program is started when the control means 118 is activated, such as when the power switch of the inverter device is turned on, the program moves from the start 210 to the short-circuit brake (B99RQ) 211 and is executed. In the description of the first embodiment, the operation when the B99RQ signal shown in FIG. 3 is generated is performed, and the short circuit braking period starts after the voltage reduction period.

  Then, when the signal Cs for determining the stop shown in FIG. 4 becomes high, the process moves to the lock release 213, where the solenoid 201 is energized, and the user can open the lid 196. Sex is secured.

  If the lid 196 can be opened by the user's operation when the power is turned on, for example, when braking of the previous operation has not been completed, the remaining rotation This creates danger to the user.

  In the present embodiment, after the power is turned on, a short-circuit braking period is passed, and the risk is eliminated by releasing the lock after the safety ensuring signal Cs by the stop determination becomes high. Thus, a highly safe washing machine can be realized.

  As described above, in this embodiment, after appropriately determining the stop of the electric motor, the lid is unlocked and the user can open the lid 196. It can be realized.

  In particular, since the brake using the B99RQ signal is performed by the short-circuit brake (B99RQ) 211, the drum 106 remains rotating immediately after the power is turned on, even in a sensorless configuration that does not use a speed sensor or a position sensor. However, since the occurrence of overcurrent and overvoltage in the inverter circuit 117 can be suppressed regardless of the speed and position (phase), it is extremely effective.

  Further, in the present embodiment, since the absolute current value is handled by using the output value of the current detection means 119 in the correct zero current state as an offset value, for example, the current detection means 119 is instructed during short-circuit braking. When the failure occurs, the inventors know that there is a high possibility that the output signal is fixed regardless of the actual current value such as 0V or 5V. In this case, the Cs signal is high. The possibility of becoming is extremely low, and high safety is ensured.

In the present embodiment, the rotation axis of the drum 106 is shown as being horizontal. However, the drum 106 is not particularly limited to horizontal, and may have a vertical or oblique rotation axis. .

  As for the power transmission path for the rotational drive of the drum 106, the one using the pulley 182 and the belt 108 is shown, but this is not limited to this configuration, the one using a gear (gear), As referred to as direct drive, it may be one that has an electric motor directly on the shaft of the drum 106 and rotates at the same speed.

  Further, the configuration of the lid locking means 200 is not limited to the configuration described in the present embodiment. For example, a plurality of lid locking means is provided, and a first lock that can be unlocked at any time by a user's handle operation. The lid locking means and the second lid locking means that is unlocked by a signal from the control means are used in combination, or the locked state is always obtained when the lid is closed. Various configurations can be used, such as the one that prevents / permits depending on the signal, and the one that the handle cannot be operated by the signal from the control means, and controls whether the user can open the lid in any case Any configuration can be used as long as it can be changed by a signal from the means, and a specific configuration can be freely designed.

(Embodiment 2)
FIG. 9 is a block diagram showing a main part of the inverter device according to the second embodiment of the present invention.

  In the present embodiment, the configuration for calculating the speed and the phase is particularly different from that in the first embodiment, but the others are the same, and therefore only the blocks different from the first embodiment will be described.

  In FIG. 9, the control unit 220 includes a speed calculation unit 221, a phase error detection unit 223 that receives Vd, Vq, Id, and Iq signals from the central control unit 135, and a variable frequency oscillation unit 127. Similarly to the first embodiment, the frequency oscillating means 127 has an amplifier 128 that has a P component and an I component and outputs a calculated speed ω, and an integrator that performs time integration of the calculated speed ω and outputs a calculated phase θ. 129 is used.

  In the present embodiment, the calculated speed ω is also input to the phase error detecting means 223, and the parameters (resistance value, maximum inductance, minimum inductance) of the electric motor 109 are stored, the voltage command value and the detected value are detected. From the current value, a phase error ε is calculated. When the calculated phase θ is advanced with respect to the actual phase, ε> 0, and when the calculated phase θ is delayed with respect to the actual phase, ε <0. Become.

  In the steady state, the control loop operates so that the input of the amplifier 128, that is, the output ε of the phase error detection means 223 becomes zero, and the speed calculation means 221 uses the current value signals Id and Iq in the rotating coordinates. In response to the voltage value signals Vd and Vq at the rotation coordinates, the speed ω and the phase θ are calculated and output.

  The calculation speed ω is calculated using the previous ω periodically calculated for each carrier frequency of the inverter circuit 117 such as 64 us, for example, so that the control loop shown in FIG. The tour has been avoided.

The configuration of other parts is the same as that of the first embodiment, and the operation when the B9RQ signal is generated is also equivalent to that of the first embodiment.
With the above configuration, in the inverter device according to the present embodiment, when the R4RQ signal is generated, Vd and Vq are set to zero with the absolute value being reduced during the voltage reduction period as in the first embodiment. Both Vd and Vq are set to zero during the short-circuit braking period.

  At this stage, since Id and Iq are considerably large, these are added to the calculation element by the phase error detection means 223, and the calculated phase θ during the short-circuit braking period is the actual phase, that is, the permanent magnets 100 and 101. It is possible to obtain an extremely accurate ω during the short-circuit braking period.

  When the speed of the drum 106 reaches a speed equivalent to 35 r / min, the calculation ω <ωth and the operation in the period until the determination of the subsequent stop, such as the J signal rising high, is described in the first embodiment. It is the same.

  In the present embodiment, as the configuration of the phase error detection means 223, since it involves a slightly complicated calculation, a processor such as a microcomputer that realizes the calculation requires a high calculation power. The error of the calculated phase θ with respect to the actual phase and the error between the actual speed and the calculated speed ω tend to be very small, and the reliability for the calculated speed ω becomes extremely high. As the determination, a highly reliable device can be realized, and an inverter device with extremely high safety can be realized.

  Further, even during a power running period other than the short-circuit braking period, even during a so-called “sensorless” operation in which the electric motor 109 does not have a position sensor or a speed sensor, the high-performance washing with excellent responsiveness of the calculated speed ω and phase θ. It can be operated as a machine, and can be shared with speed calculation and phase calculation during power running operation, which is rational.

  During the short-circuit braking period, the input voltage of the electric motor 109 is almost zero, and Vd and Vq are both fixed to zero. Therefore, the control configuration is slightly different from that during power running, and the calculation of the speed to a lower speed is performed. For example, the gain (for proportional component, integral component, etc.) used in the error amplifier for feeding back the phase error may be switched to a value different from that during powering.

  Of course, it is also possible to use an inverter device using a position sensor such as a Hall IC, and it is possible to ensure multiple safety in consideration of the case where the position sensor used for determination of stoppage in the past should break down. It will be possible to ensure excellent safety.

  In the present embodiment, the phase error ε in the phase error detection means 223, that is, the physical quantity that is the dimension of the angle is calculated, but it is sufficient to use only the voltage component in the direction of the calculated magnetic flux, for example. Since the number of various calculations such as addition / subtraction / multiplication / division, trigonometric functions, exponential functions, and complex number operations can be reduced, simpler calculations can be achieved.

  In addition, the two orthogonal axes generally called vector control are often configured to match the direction of the magnetic flux generated by the permanent magnets 100 and 101, but are particularly limited to a configuration that perfectly matches the d-axis that is the magnetic flux axis. For example, a value different from the actual inductance value possessed by the electric motor 109 may be used as a reference with an axis slightly advanced in phase from the d axis, and the permanent magnets 100 and 101 rotate. The electric motor 109 configured to be embedded deep inside the child also has an advantage that current can be rationally reduced.

Based on the voltage equation of a general permanent magnet motor, the error ε is calculated against the voltage error, current error, speed error, inductance value error, resistance error, etc., and the error ε converges to zero You can use a simplified formula that eliminates terms that have a small effect on performance in actual work, etc. in any case, and in any case, the microcomputer to be used is as much as the calculation work is reduced It has the advantage that it can be configured with low power, low cost, and low power consumption.

  As described above, the washing machine according to the present invention does not use a position detector such as a Hall IC (a so-called “sensorless” method and configuration) is simple and low-cost but sufficiently safe. Thus, the user is allowed to open the lid, and a highly safe washing machine can be realized.

  In addition, a drum for putting a material to be dehydrated, such as clothes, has a drum with a horizontal, vertical, or rotating shaft having an angle as a load, and can be applied to what is called a dehydrator, a washing dryer, or the like.

100, 101 Permanent magnet 105 Clothing 106 Drum 109 Motor 196 Lid 200 Lid lock means 111, 112, 113, 114, 115, 116 Switching element 117 Inverter circuit 118, 170 Control means 119 Current detection means 120, 171 Speed calculation means 102, 103, 104 Winding 127 Variable frequency oscillation means 126, 213 Phase error detection means 150, 158 Coordinate conversion means

Claims (5)

A drum for accommodating the clothing, an electric motor for driving the drum has a permanent magnet and a winding, and a lid for opening and closing the opening of the drum, and a lid locking means for locking the lid, a plurality of switching elements And an inverter circuit that supplies current to the electric motor, and control means that controls on / off of the switching element. The control means includes current detection means that detects the current, and outputs of the current detection means. And a speed calculating means for calculating the speed of the electric motor, and the control means controls the switching element so as to keep the input voltage of the electric motor at substantially zero during the braking period of the drum, Is a washing machine that allows the user to open the lid after the lid lock means is below a predetermined value ,
The said control means is a washing machine which has the voltage reduction period which controls the said switching element so that the absolute value of the input voltage of the said motor may be lowered | hung before the said braking period . The electric motor has three-phase windings, the current detection means detects a current of two or more phases among the three phases, and the speed calculation means detects a current of two or more phases of the three phases. The washing machine according to claim 1, wherein the speed is calculated based on the value. Variable frequency oscillation means for outputting the phase of the permanent magnet including the time integral value of speed, phase error detection means, and coordinate conversion means, wherein the current detection means is a current of two or more phases of three phases. The coordinate conversion means converts the output of the current detection means from stationary coordinates to rotation coordinates using the phase, and outputs the current value signal at the rotation coordinates. The washing machine according to claim 2, wherein the speed is calculated. The washing machine according to any one of claims 1 to 3 , wherein after the power is turned on, the brake locking period is set before the user can open the lid of the lid locking means. The washing machine according to any one of claims 1 to 4 , wherein the electric motor has a sensorless system having no position detector.