JP2012130111A - Electric machine control apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric machine control apparatus which achieve a short-cut braking in which transient peak current is suppressed.SOLUTION: An electric machine control apparatus comprises: a permanent magnet 26 and 27; three terminals UVW; an electric machine 25 which includes three-phase coils 30, 31 and 32 having one end of each coil connected to three terminals UVW, respectively; and a short-cut circuit 54 which includes a plurality of switching elements 41, 42, 43, 44, 45 and 46 and is connected to three terminals UVM. The short-cut circuit 54 includes a short-cutting period between two lines during which a short-cut is performed between two terminals of the three terminals UVW, and then a short-cutting period among three lines during which a short-cut is performed between three terminals when controlling the electric machine 25. Therefore, the electric machine control apparatus can control transient peak current.

Description

  The present invention is used in, for example, an electric washing machine, and drives an rotator called a drum in an electric machine and operates the electric machine as a brake when stopping or decelerating the rotator. It is about.

  Conventionally, in this type of electric machine control device, the inverter circuit is driven by connecting the output to a three-phase electric machine, and when the dehydration is completed or when the device is already inertially rotated when the power is turned on. When braking is applied, control is performed so that three switching elements in the inverter circuit are simultaneously turned on so as to short-circuit the terminals of the electric machine (for example, refer to Patent Documents 1 and 2). .

  FIG. 10 is a block diagram of a conventional electric machine control device described in Patent Document 1. In FIG.

  As shown in FIG. 10, conventionally, this type of electromechanical control device is provided with a rectifier circuit 2 connected to an AC power source 1, a coil 3 connected to the output of the rectifier circuit 2, and a capacitor 4. The inverter circuit 5 to which the voltage is supplied has an output connected to the electric machine 6, and the control means 7 supplies the current supplied to the three-phase windings 9 a, 9 b and 9 c in the electric machine 6 through the drive circuit 8. The six switching elements 10a, 10b, 10c, 10d, 10e, and 10f in the inverter circuit 5 that controls the above are turned on and off.

  The control means 7 performs on / off of each switching element using position detection signals from the position detection means 11a, 11b, and 11c. Further, the control means 7 further includes input from the input setting means 12 and the water level detection means 13. The signal is received, the signal is output to the display means 14 and the load driving means 15, and the load driving means 15 operates as a washing machine by controlling the on / off of the current to the drain valve 16.

  Accordingly, when applying braking (electromagnetic braking) using an electric machine, the three-phase windings 9a, 9b of the electric machine 6 are turned on simultaneously by turning on the switching elements 10d, 10e, and 10f of the inverter circuit 5. 9c uses short-circuit braking in which the connection terminal with the inverter circuit 5 is short-circuited.

JP 2002-159882 A JP 2003-275494 A

  However, in the conventional configuration, when the characteristics of the electric machine, especially the inductance component is designed to be small, the current flowing through the electric machine and the switching element in the inverter circuit becomes transiently large when short-circuit braking is performed. , Including the problem of reliability that permanent magnets used in electric machines demagnetize or break beyond the current rating of the switching element, or if it has an overcurrent protection circuit, it also operates and includes braking operation It had the user-friendliness of stopping operation and safety issues.

  FIG. 11 shows a one-phase current waveform diagram of a conventional electromechanical control device. In FIG. 11, a U-phase current waveform which is one of the three-phase currents showing an example of the above-described problem. FIG.

  In FIG. 11, the horizontal axis represents the time from the time when the switching elements 10d, 10e, and 10f are simultaneously turned on, and the V-phase line current Iv is transiently changed to 18A immediately after the three-phase short circuit state. The peak current falls within a steady state after approximately 25 ms, and the peak current falls within the range of 10 A for both positive and negative.

  In FIG. 11, since the moment of inertia of the load is large, there is almost no deceleration during a period of about 25 ms, and the deceleration of the electric machine by braking gradually proceeds thereafter.

  FIG. 12 is a current waveform diagram in which three-phase currents are written together.

  When three-phase terminals (between three wires) are short-circuited at the same time, an imbalance occurs between the three phases depending on the phase of the short-circuit timing. As a result, the peak of one line current is higher than the other two phases. It becomes large and higher than the steady short-circuit current.

  In addition, regarding the polarity of the peak current value, that is, the direction, the difference in peak value between the direction from the inverter circuit 5 toward the electric machine 6 and the current in the reverse direction occurs depending on the timing of the short circuit.

  Therefore, as the current capacity of the switching elements 10d, 10e, and 10f, the one having no problem even through the positive and negative peak currents when the absolute value is maximized is used.

  The present invention solves the above-described conventional problems, and suppresses overcurrent that occurs transiently in short-circuit braking, thereby preventing demagnetization of permanent magnets used in electric machines and destruction of switching elements, and reliability. Another object of the present invention is to provide an electromechanical control device that is high in operation, prevents interruption of operation including braking due to operation of an overcurrent protection circuit, is excellent in usability, and has high safety.

  In order to solve the above-described conventional problems, an electromechanical control device according to the present invention includes a permanent magnet, three terminals, an electric machine having a three-phase winding having one end connected to the terminals, and a plurality of switching devices. A short-circuit having an element and connected to the three terminals, the short-circuit being short-circuited between two terminals of the three terminals during braking of the electric machine; The three terminals are configured to have a three-wire short-circuit period.

  The electric machine control device of the present invention includes a permanent magnet, three terminals, an electric machine having a three-phase winding having one end connected to the terminal, a plurality of switching elements, and the three terminals. And a position detection means for detecting an electrical angle corresponding to the phase of the magnetic flux of the permanent magnet interlinked with the winding, and the short-circuit circuit includes the position detection means during braking of the electric machine. When the output signal is within a predetermined range, the three terminals are short-circuited to enter a three-wire short-circuit period.

  This reduces the peak value of current that flows transiently during braking, prevents demagnetization of permanent magnets used in electric machines, prevents destruction of switching elements due to overcurrent, and has an overcurrent protection circuit In addition, the operation stop due to the operation can be prevented, and an electromechanical control device with high reliability and safety can be realized.

  The electromechanical control device of the present invention reduces the peak value of a current that flows transiently during braking, prevents demagnetization of a permanent magnet used in an electric machine, prevents breakdown due to overcurrent of a switching element, and overcurrent. Even when the protective circuit is provided, it is possible to prevent the operation from being stopped due to the operation, and to realize an electromechanical control device with high reliability and safety.

1 is a block diagram of an electromechanical control device according to Embodiment 1 of the present invention. Operation waveform diagram of the electromechanical control device Current waveform diagram of the electromechanical control device The block diagram of the electromechanical control apparatus in Embodiment 2 of this invention The block diagram of the electromechanical control apparatus in Embodiment 3 of this invention Operation waveform diagram of the electromechanical control device The block diagram of the electromechanical control apparatus in Embodiment 4 of this invention Operation waveform diagram of the electromechanical control device Transient current waveform diagram of the same electromechanical control device Block diagram of a conventional electromechanical control device 1-phase current waveform diagram of the same electromechanical control device Three-phase current waveform diagram of the same electromechanical control device

  A first invention includes a permanent magnet, three terminals, an electric machine having a three-phase winding having one end connected to the terminal, and a short circuit having a plurality of switching elements and connected to the three terminals. The short circuit includes a three-wire short-circuit period for short-circuiting the three terminals after a two-wire short-circuit period for short-circuiting two of the three terminals during braking of the electric machine. By using the electromechanical control device, it is possible to effectively suppress an overcurrent that occurs transiently during braking.

  According to a second aspect of the invention, in particular, in the first aspect of the invention, there is provided position detecting means for detecting an electrical angle corresponding to the phase of the magnetic flux of the permanent magnet interlinked with the winding, and the two-line short circuit period and the three-line short circuit are provided. By using an electromechanical control device that starts when the output signal of the position detection means falls within a predetermined range during at least one of the periods, the overcurrent during braking can be reliably suppressed with a relatively simple configuration. It will be a thing.

  According to a third aspect of the invention, in particular, in the first aspect of the invention, a current detection unit that detects at least one phase current is provided, and at least one of the two-wire short circuit period and the three-line short circuit period is predetermined by the current detection unit. By using an electromechanical control device that starts when the range is reached, an overcurrent during braking can be reliably suppressed with a relatively simple configuration.

  According to a fourth aspect of the present invention, in particular, in any one of the first to third aspects, the short circuit is configured by a three-phase inverter circuit having six switching elements, and the inverter circuit is in a two-line short circuit period. By making the electromechanical control device to turn on two switching elements on the low potential side of the six switching elements, power running to operate the electric machine as an electric motor is possible, and with a relatively simple configuration, A braking operation can also be performed, and a sufficient effect of reducing a transient overcurrent by providing a two-wire short-circuit period during braking can be obtained.

According to a fifth aspect of the present invention, there is provided a permanent magnet, three terminals, an electric machine having a three-phase winding having one end connected to the terminal, and a short circuit having a plurality of switching elements and connected to the three terminals. And a position detection means for detecting an electrical angle corresponding to the phase of the magnetic flux of the permanent magnet interlinked with the winding, and the short circuit has a predetermined output signal from the position detection means during braking of the electric machine. By using an electromechanical control device that enters a three-wire short-circuit period that short-circuits the three terminals when the range is reached, it is possible to suppress overcurrent that occurs transiently during braking with a relatively simple configuration. It will be a thing.

  In a sixth aspect of the present invention, in particular, in any one of the first to fifth aspects, the short circuit is configured by a three-phase inverter circuit having six switching elements, and the inverter circuit is in a three-line short circuit period. The electric machine control device that turns on three switching elements on the low potential side of the six switching elements enables powering to operate the electric machine as an electric motor, and has a relatively simple configuration. A braking operation can also be performed, and a transient overcurrent reduction effect during braking can also be obtained.

  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 electromechanical control device according to a first embodiment of the present invention.

  1, the electromechanical control device of the present embodiment includes a full-wave rectifier circuit 22 connected to a 220-V AC power source 21, an inverter circuit 23 that receives a 280-V DC voltage Vdc from the rectifier circuit 22, and an inverter circuit. The capacitor 24 for stabilizing the DC voltage of the input 23 and the electric machine 25 that receives the AC current that is the output of the inverter circuit 23, and the like. The electric machine 25 has a rotor 33 having permanent magnets 26 and 27 as its constituent elements, and a stator 33 composed of three-phase windings 30, 31 and 32 of U, V and W. Further, a position detection means 34 using a Hall IC is provided. The position detection means 34 detects an electrical angle θ corresponding to the phase of the magnetic flux of the permanent magnets 26, 27 interlinked with the windings 30, 31, 32.

  As a reference point for θ = 0, a configuration in which the magnetomotive force due to the current supplied from the U-phase terminal to the electric machine is in the same direction as the magnetic flux by the permanent magnets 26 and 27 is often used. For example, if the general configuration of using three Hall ICs to output high and low with the polarities of the opposed permanent magnets 26 and 27, from the change in logic of the three outputs, It can be detected that the electrical angle θ has reached the position of every 60 degrees, and it can be known from any combination of static logic that the position is somewhere within the range of the electrical angle of 60 degrees. It will be a thing.

  In addition to the full-wave configuration, the rectifier circuit 22 may be a double voltage type that can obtain a DC voltage of several tens of volts from an AC power source having an effective value of 100 V, for example. A configuration in which a booster circuit is used together may be used so that a higher voltage is used as the DC voltage.

  The shaft output of the electric machine 25 is transmitted to a large pulley 37 having a diameter 8.25 times that of the small pulley 35 through a small pulley 35 and a rubber belt 36, and rotationally drives a drum 38 into which laundry enters. The drum 38 is configured to operate as a drum-type washing machine that stores clothes together with water and performs washing / dehydration.

However, the rotation axis of the drum 38 is substantially horizontal, or the drum 38 has a substantially vertical rotation axis in addition to what is called a drum-type washing machine in which the rotation axis is approximately horizontal or has an inclination of about 5 to 30 degrees from the horizontal. There is also a so-called vertical washing machine, which is not particularly limited to a washing machine, but even in an electromechanical control device that operates as a washing machine, the drum 38 is provided in various ways. It is something that can be done.

  The inverter circuit 23 is provided with six stone switching elements 41, 42, 43, 44, 45, 46 and a vector control means 50 using IGBT, and further, a first short-circuit control means 51 and a second short-circuit control means. 52, the braking signal generating means 53 is provided, and in the present embodiment, the short circuit 54 is configured using the inverter circuit 23 as it is.

  The vector control means 50 uses the phase signal θ from the position detection means 34, the first current component I 1 having a phase substantially equal to the magnetic flux generated in the electric machine 25 by the permanent magnets 26, 27, and the permanent magnets 26, 27. Are supplied to the electric machine 25 by being divided into second current components I2 having a phase substantially orthogonal to the magnetic flux of the switching element 41, 42, 43, 44 so as to be equal to the input I1 * and I2 *. 45, 46, signals UP, VP, WP, UN, VN, WN are output.

  In general, a configuration for controlling the current values of two axes perpendicular to each other of the d-axis current and the q-axis current is used in vector control, but the vector control means 50 is equivalent to that and is not shown in FIG. However, for example, what detected the current of each of the three phases with a resistor or the like is decomposed into a first current component (d-axis current) and a second current component (q-axis current) by three-phase / two-phase conversion. However, it is realized by controlling each of them to be equal to the set values I1 * and I2 *.

  The first short-circuit control means 51 includes a first short-circuit signal generating means 60, AND circuits 61 and 62, OR circuits 63 and 64, and a NOT circuit 65. A phase signal θ from the detection means 34 is input, and a first short-circuit signal S1 that is high during normal power running and low during a two-wire short-circuit period and a three-wire short-circuit period during braking is output.

  The second short-circuit control means 52 includes second short-circuit signal generating means 70, AND circuits 61 and 62, OR circuits 63 and 64, and NOT circuit 65. The first short-circuit signal generating means 60 is A phase signal θ from the detection means 34 is input, and a second short-circuit signal S2 that is high during normal power running and low during a three-wire short-circuit period during braking is output.

  The AND circuit, the OR circuit, the NOT circuit, and the like are indicated by hardware circuit symbols, but may be realized by software in a microcomputer, for example.

  The braking signal generation means 53 inputs the braking signal S0 to the vector control means 50, the first short circuit signal generation means 60, and the second short circuit signal generation means 70, and during normal operation (powering). High is output during low and braking.

  About the electromechanical control apparatus comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  During normal operation, that is, during power running, the braking signal S0 from the braking signal generation means 53 is low, and the vector control is performed by the logic circuit configuration inside the first short-circuit control means 51 and the second short-circuit control means 52. The UP, VP, WP, UN, VN, and WN signals output from the means 50 are transmitted to the switching elements 41, 42, 43, 44, 45, and 46 as they are, and are turned on / off by logic high / low. As a result of the control, the electrical power in the electrical machine 25 is converted into mechanical power.

  FIG. 2 shows an operation waveform diagram of the electromechanical control device of the present embodiment. FIG. 2 is an operation waveform diagram when the brake is entered from the state where the washing machine is dehydrated and the drum 38 is rotating at a high speed using the weak magnetic field. The output θ of the means 34, (A) indicates the braking signal S0, (C) indicates the first short circuit signal S1, and (D) indicates the second short circuit signal S2.

  At t0, the braking signal S0 changes from low to high and moves from power running to a braking command, but S1 continues to be high until θ next reaches 115 degrees, and when θ reaches 115 degrees at t1. Thus, S1 changes to low.

  According to the logic of the first short-circuit control means 51, the switching elements 41 and 42 are turned off and the switching elements 44 and 45 are turned on regardless of the output of the vector control means 50 after t1, so that the electric machine 25 is The two lines U and V are short-circuited by the switching elements 44 and 45.

  At t2, which is the timing at which θ further advances 60 degrees from t1, the second short-circuit signal S2 changes from high to low, and the logic of the second short-circuit control means 52 causes the vector control means 50 to perform after t2. Regardless of the output, the switching element 43 is turned off, the switching element 46 is turned on, and in addition to the two lines U and V that have already been short-circuited by the first short-circuit control means 51, The switching elements 44, 45, and 46 are short-circuited.

  Therefore, in the present embodiment, the short circuit 54 is configured by the inverter circuit 23, and the two-wire short-circuit period T2 in which two of the three terminals UVW are short-circuited when the electric machine 25 is braked. The inverter circuit 23 turns on the two switching elements 44 and 45 on the low potential side of the six switching elements 41 to 46 during the short-circuit period T2 between the two lines.

  Then, after the two-line short-circuit period T2, the three-terminal short circuit period T3 for short-circuiting the three terminals UVW is provided, and the three switching elements 44, 45 on the low potential side among the six switching elements 41 to 46 are provided. 46 is turned on.

  Therefore, in the present embodiment, both the two-wire short-circuit period T2 and the three-wire short-circuit period T3 start when the output signal of the position detection means 34 falls within a predetermined range.

  In addition, the 3-line short-circuit period T3 is continued until the braking operation, that is, the electric machine 25 absorbs all the kinetic energy of the drum 38 and the like and the speed becomes zero, and the 3-line is short-circuited. Therefore, the regenerative operation in which the voltage of the capacitor 24 is charged from the inverter circuit 23 does not occur, and the voltage Vdc of the capacitor 24 does not become an excessive value.

  Actually, the braking torque is effectively generated from the three-wire short-circuit period T3, and the start of braking is delayed by the delay time from the time when S0 becomes high.

  However, in the case of a washing machine, since the moment of inertia of the load is large due to the drum 38 and the dehydration operation is performed at a high speed, the time required for the drum 38 to completely stop from the start of braking, The delay time at the start of the above-mentioned braking becomes a very small ratio, and the discoloration in terms of braking performance can be ignored.

FIG. 3 is a current waveform diagram of the electromechanical control device according to the present embodiment. FIG. 3 is a waveform diagram of the current flowing into the electric machine 25. The point where the peak value of the line current is the maximum on the plus side and the absolute value is the maximum is the V-phase current of + 11A, and the absolute value on the minus side At the point where the value is maximum, the W-phase current is -10A.

  These values are kept 38% lower than the absolute peak current value 18A generated in the prior art, and the reliability is reduced by reducing the current flowing through the switching elements 41 to 46, or the switching element used Cost reduction by reducing current rating, further improvement in reliability by preventing demagnetization of permanent magnets 26 and 27 constituting electric machine 25, or cost reduction by reducing demagnetization tolerance of permanent magnet used. It becomes.

  In the present embodiment, the timing t1 is set to θ = 115 degrees, the timing t2 is set to θ = 175 degrees, and the T2 period is set to correspond to the electrical angle θ of 60 degrees. The value of θ that effectively suppresses the peak current value varies depending on the speed, number of poles, shape, inductance, resistance value, and various other specifications of the electric machine 25. For example, a technique of grasping and designing an effective θ value by a preliminary test is effective.

  Further, the resolution as the θ value is not as fine as, for example, an electrical angle of 1 degree, and even if it is a rough value such as an electrical angle of 60 degrees, a certain effect can be obtained. In the case where the position detecting means 34 using the Hall IC is provided, it is possible to start the short circuit period between the two lines or the short circuit period between the three lines from the time when the output logic becomes a predetermined combination. However, compared with a configuration in which the starting condition θ is completely ignored and a two-wire short-circuit period or a three-wire short-circuit period is provided, an effect that the transient current can be reduced can be expected.

  Actually, the start timing of the two-wire short-circuit period or the three-wire short-circuit period is controlled by the processing by the microcomputer program. Therefore, as one of the confirmation methods, for example, several tens to several hundred times When the braking start operation is performed and the θ value at that time or the position detection means 34 has three Hall ICs, there are six combinations for each electrical angle of 60 degrees which is the resolution of the combination of the output logic. If it is distributed evenly, if it turns out that there is no processing at first and there is a tendency to shift to a specific combination, it turns out that the microcomputer program is going to control some start timing. It can be a method for performing analysis work or debugging.

(Embodiment 2)
FIG. 4 shows a block diagram of an electromechanical control device according to the second embodiment of the present invention.

  In FIG. 4, the electric machine 25 having the same configuration as that of the first embodiment is provided, and switching elements 81 and 82 constituted by relays, a relay drive circuit 83, and a braking signal generating means 84 are provided as the short circuit 80. ing.

  The relay drive circuit 83 switches the relay when the signal θ from the position detection unit 34 reaches a first predetermined range after the time when the braking signal S0 from the braking signal generation unit 84 is received. The switching element 81 used is turned on, and when the second predetermined range is reached, the switching element 82 using a relay is also turned on.

As a result, the electromechanical control device according to the present embodiment enters a two-wire short-circuit period in which the terminals of U and W are short-circuited when the relay drive circuit 83 turns on the switching element 81, and then the switching element 82. In the state where the switch is also turned on, the three-wire short-circuit period in which all the UVW terminals are short-circuited is entered.

  As a result, the peak value of the current is suppressed with respect to the configuration in which the three wires are suddenly short-circuited at an arbitrary phase, thereby preventing the overcurrent that causes demagnetization of the permanent magnets 26 and 27 from flowing. It will be possible.

  In this embodiment, since both of the two switching elements are configured to use relays, it can be used relatively easily in a device that does not use an inverter circuit, and both relays are in an off state. If a device with a high withstand voltage is used, there is an advantage that it can be applied to a device including a state with a high induced electromotive force.

  However, since there is a delay time in the turn-on operation of the relay, if the frequency at the time of entering the braking operation is high, a deviation of the electrical angle may occur. For this reason, a configuration for correcting the turn-on delay time as needed may be effective.

(Embodiment 3)
FIG. 5 is a block diagram of an electromechanical control device according to the third embodiment of the present invention.

  In FIG. 5, the short circuit 90 is constituted by an inverter circuit 91, and the inverter circuit 91 includes current detection means 92 that detects an instantaneous value of each UVW current.

  In the present embodiment, the current detection means 92 is constituted by shunt resistors 93, 94, 95 connected to the emitter terminals of the three switching elements 44, 45, 46 on the low potential side, and an amplifier circuit 96. In synchronization with the alternating on / off operation of the high-potential side switching elements and the low-potential side switching elements of each phase, generally called PWM (pulse width modulation), just in the on period of the low-potential side switching elements 44 to 46 Since the line current of each phase flows to each shunt resistor 93 to 95, the voltage generated between the terminals of each shunt resistor 93 to 95 is converted by the amplifier circuit 96, and a signal is output as the current value of each phase. It has become.

  The first short-circuit control means 101 is provided with a first short-circuit signal generating means 102, the second short-circuit control means 103 is provided with a second short-circuit signal generating means 104, and the other The configuration is the same as that of the first embodiment.

  The first short circuit signal generation means 102 receives the current signal from the current detection means 92 and is high during normal powering, and low during the two-wire short-circuit period and the three-wire short-circuit period during braking. The signal S1 is output.

  The second short circuit signal generation means 104 receives the current signal from the current detection means 92, and outputs a second short circuit signal S2 that is high during normal power running and low during a three-wire short circuit period during braking. To do.

  The vector control means 105 performs current vector control by dividing the current into Id and Iq from the current signal of each phase from the current detection means 92 and θ input from the position detection means 34.

  The braking signal generation means 106 inputs the braking signal S0 to the vector control means 50, the first short circuit signal generation means 102, and the second short circuit signal generation means 104, and during normal operation (powering). High is output during low and braking.

  In the above configuration, the operation of the present embodiment will be described.

  FIG. 6 shows an operation waveform diagram of the electromechanical control device of the present embodiment. FIG. 6 shows an operation waveform diagram when the vehicle enters the braking state from the state where it is powered by the weak magnetic field and is rotating at a high speed. (A) is the UVW line currents Iu, Iv, Iw from the inverter circuit 90 to the electric machine 25, (A) is the induced electromotive force Eu, Ev, Ew, as viewed from the common terminal n of the windings 30, 31, 32. (C) is an output voltage waveform Vu, Vv, Vw of the inverter circuit 90 viewed from the minus terminal of the capacitor 24, (d) is a braking signal S0 from the braking signal generation means 106, and (e) is a first short circuit signal generation. The output S1 from the means 102, (f) shows the output S2 from the second short circuit signal generating means 104.

  In general, in the vector control, at a position of θ = 0, the magnetomotive force vector due to the current Iu flowing from the U-phase terminal of the electric machine takes a point in the same direction as the magnetic flux of the permanent magnets 26 and 27. In the present embodiment, the vector control means 105 performs vector control with θ = 0 at the Z point in (A), and switching on the low potential side of the phase that is the lowest potential among the three phases of UVW. While one of the elements 44, 45, 46 is kept on for the period of 120 electrical degrees in order, the voltage waveform of (c) appears by the other two-phase PWM (pulse width modulation). A substantially sinusoidal voltage is applied between them.

  On the other hand, as shown in (D), when the braking signal generating means 106 raises the S0 signal from low to high at t0 and issues a braking command, the first short circuit signal generating means 102 At the timing t1 of the point Ziu where the Iu signal from the current detection means 92 for detecting the current waveform shifts from negative to positive, the output S1 is changed from high to low as shown in (e), and the two-wire short-circuit period T2 is reached. It will be entered.

  Further, the second short-circuit signal generating means 104 outputs the Iv signal from the current detecting means 92 for detecting the current waveform of (a) at the timing Z2 at the point Ziv where the current waveform shifts from negative to positive as shown in (f). S2 is changed from high to low, and the three-wire short-circuit period T3 is entered.

  Thus, in the present embodiment, the two-wire short-circuit period and the three-wire short-circuit period are started from the zero point of the line current value input from the current detection means 92. Compared with the configuration that suddenly enters the 2-line short-circuit period or 3-line short-circuit period at any phase by starting the 2-line short-circuit period or the 3-line short-circuit period from the point where the current becomes zero, An effect is obtained in that the transient current is significantly suppressed.

  In general, in order to power the electric machine 25, it is necessary to input some voltage. In FIG. 6, the voltage waveform is as shown in (c), but the phase of the voltage falls within a predetermined range. At this point, the transient current tends to be suppressed even in the configuration in which the two-line short circuit period or the three-line short circuit period is entered.

  In this embodiment, since the detection output of the current detection means 92 that is a more direct cause is used for the transient current, a large effect can be obtained as an effect of suppressing the transient current.

  The determination that the line current of one phase detected by the current detection unit 92 becomes zero is, for example, as a realistic design, when the absolute value is less than a predetermined value or when the sign of the current value is the previous time It is necessary to distinguish between two points from positive to negative and from negative to positive, so that the current of the three-phase current of the current detection means 92 is different. The configuration is such that the combination of the sign of the values is when a predetermined condition is met, and the state is started when the current detection means 92 is within the predetermined range.

  However, the timing is not always the optimum condition in any configuration of the electric machine 25, that is, the condition that the transient current is most suppressed, the inductance value, the resistance value of the windings 30, 31, 32, the permanent magnet 26, It is more effective that the condition for suppressing the transient current due to various factors of the electric machine 25 such as the magnitude of the magnetic flux 27 starts from a time other than the timing at which the line current value of a certain phase becomes zero. Sometimes it works.

  The configuration used in the present embodiment uses the vector control means 105, but is not necessarily limited to that by vector control, and the position detection means 34 also has a two-wire short-circuit period or a three-wire The timing for starting the short-circuiting period is unnecessary, so it may not be provided as hardware, and it does not matter whether it is provided in the program (software) in the microcomputer.

(Embodiment 4)
FIG. 7 is a block diagram of an electromechanical control device according to the fourth embodiment of the present invention.

  In FIG. 7, the short circuit 110 is constituted by an inverter circuit 111. In the inverter circuit 111, the short-circuit control unit 115 includes a short-circuit signal generation unit 116, AND circuits 120, 121, 122, OR circuits 123, 124, 125, and a NOT circuit 126. Other configurations are the same as those in the first embodiment.

  The short circuit signal generator 116 receives the position signal θ from the position detector 34, and outputs a short circuit signal S3 that is high during normal power running and low during a three-wire short circuit period during braking. The vector control means 50 and the braking signal generation means 53 are the same as those in the first embodiment. The braking signal generating means 53 inputs the braking signal S3 to the vector control means 50 and the short circuit signal generating means 116, and outputs low during normal operation (powering) and high during braking. ing.

  FIG. 8 shows an operation waveform diagram of the electromechanical control device of the present embodiment. FIG. 8 is an operation waveform diagram when the washing machine is dehydrated and the drum 38 is rotated at a high speed using the weak magnetic field, and enters the braking state. The output θ of the means 34, (b) the braking signal S0, and (c) indicate the short circuit signal S3.

  At t0, the braking signal S0 changes from low to high and moves from power running to a braking command, but S3 continues to be high until θ next reaches 220 degrees, and when θ reaches 220 degrees at t3. Thus, S3 changes to low. Due to the logic of the short-circuit control means 115, the switching elements 41, 42, 43 are turned off and the switching elements 44, 45, 46 are turned on regardless of the output of the vector control means 50 after t3. , UVW three lines are short-circuited by the switching elements 44, 45, 46.

  Therefore, in the present embodiment, the circuit is configured by the short circuit 110 and the inverter circuit 111, and has a three-wire short-circuit period T3 in which the three terminals UVW are short-circuited when the electric machine 25 is braked. The three switching elements 44, 45, and 46 on the low potential side of -46 are turned on, and the three-wire short-circuit period T3 is started when the output signal of the position detection means 34 falls within a predetermined range. Become.

  FIG. 9 shows a transient current waveform diagram of the electromechanical control device of the present embodiment. FIG. 9 shows a transient current waveform diagram when shifting to braking.

  With respect to the positive side current, the U-phase positive side current, that is, the peak value of the current that flows through the diode portion inside the switching element 44 and flows into the winding 30 is 16.1A, which is 10% that of the prior art. .5% reduction. As for the minus side current, the peak value of the current drawn from the windings 31 and 32 through the IGBT side in the switching elements 45 and 46 through the minus side current of the V phase and the W phase is 15.2A. Thus, a reduction effect over the diode portion can be expected.

  In general, the reliability of surge currents is often more severe with IGBTs than with diodes. Therefore, it may be advantageous to set timing conditions so that the negative side of transient currents can be suppressed.

  As described above, in this embodiment, the start timing of the three-wire short-circuit period T3 is within a predetermined range of θ. Since the peak value can be reduced by about 10%, the cost can be reduced by reducing the current rating of the switching element, or the reliability can be improved, and the demagnetization of the permanent magnets 26 and 27 can be prevented. It becomes possible.

  In the first to fourth embodiments, the configuration in which the two-wire short-circuit period or the three-wire short-circuit period is started with one electrical angle within 360 degrees has been described. It is also possible to select one start timing from a plurality within 360 degrees.

  For example, in the fourth embodiment, due to the symmetry of the electric machine 25, even when the timing of t3 is shifted by a multiple of 120 degrees, the phase in which the transient current is generated is switched, which is almost the same. The characteristic that can be suppressed to the peak current value is obtained, and, for example, when it is shifted by 180 degrees, the current waveform is almost upside down.

  Therefore, instead of always starting the 3-wire short-circuit period at the timing of θ = 220 degrees, it is possible to switch between θ = 100 degrees, 220 degrees, and 340 degrees and use the peak current because they are shifted by 120 degrees from each other. However, when using a component called a power module in which six switching elements are assembled in one package, the three phases are made with equal specifications. ,No problem.

  Moreover, even if it is the structure which selects one from (theta) shifted every 60 degree | times, as an electric machine 25, it becomes a peak value of the substantially equivalent transient current, and it is larger by either the diode part of an switching element, or IGBT part. Only the peak flows or changes, but this is very often a problem as a power module and can be designed. In this way, even if it jumps within 360 degrees, it can be said that the electric angle θ at which the short-circuit operation is started is limited when it reaches a predetermined range.

  The same applies to the start timing of the two-wire short-circuit period provided in the other embodiments, and the selection from the skip timing may be performed within 360 degrees.

  As described above, the electromechanical control device according to the present invention can prevent generation of excessive current during braking, and can ensure reliability and provide excellent braking performance. It is applicable also to uses, such as a washing machine used.

23 Inverter circuit 25 Electric machine 26, 27 Permanent magnet 30, 31, 32 Winding 41, 42, 43, 44, 45, 46 Switching element 54 Short circuit

Claims (6)

An electrical machine having a permanent magnet, three terminals, a three-phase winding having one end connected to the terminal, and a short circuit having a plurality of switching elements connected to the three terminals, the short circuit The circuit is an electromechanical control device having a three-line short-circuit period for short-circuiting the three terminals after a two-line short-circuit period for short-circuiting between two of the three terminals during braking of the electric machine. Position detecting means for detecting an electrical angle corresponding to the phase of the magnetic flux of the permanent magnet linked to the winding is provided, and at least one of the two-wire short-circuit period and the three-wire short-circuit period is an output signal of the position detecting means. The electromechanical control device according to claim 1, wherein the electromechanical control device starts when the predetermined range is reached. The electric machine according to claim 1, further comprising: current detection means for detecting current of at least one phase, wherein at least one of the two-wire short-circuit period and the three-wire short-circuit period starts when the current detection means reaches a predetermined range. Control device. The short circuit is composed of a three-phase inverter circuit having six switching elements, and the inverter circuit turns on two switching elements on the low potential side of the six switching elements during a two-line short circuit period. The electromechanical control device according to claim 1. An electric machine having a permanent magnet, three terminals, a three-phase winding having one end connected to the terminal, a short circuit having a plurality of switching elements connected to the three terminals, and the winding Position detecting means for detecting an electrical angle corresponding to the phase of the magnetic flux of the permanent magnets that are linked to each other, and the short circuit is configured when the output signal of the position detecting means falls within a predetermined range during braking of the electric machine. An electromechanical control device that enters a three-wire short-circuit period for short-circuiting three terminals. The short circuit is composed of a three-phase inverter circuit having six switching elements, and the inverter circuit turns on three switching elements on the low potential side of the six switching elements during a three-wire short circuit period. The electromechanical control device according to any one of claims 1 to 5.