JP4867290B2 - 3-level voltage reversible chopper device - Google Patents

Description

  The present invention relates to a power conversion device, and more particularly to a three-level voltage reversible chopper device capable of obtaining a three-level DC output voltage.

Conventionally, in a DC motor control device or an energy storage device using a reactor, as described in Non-Patent Document 1, as a power conversion circuit, a so-called voltage in which the polarity of the voltage changes while the current direction is constant. A reversible chopper (two-quadrant chopper) circuit is known. An example of the voltage reversible chopper circuit is shown in FIG.
First, the operation principle will be described. FIG. 10 shows an operation when outputting a positive DC voltage.

A gate control signal as shown in FIG. 10A is given to the two semiconductor switching elements 10A and 10C. As shown in FIG. 10B, during the period I in which both 10A and 10C are turned on, the load device 3 is connected to the DC power source 1, and the output voltage becomes the DC power source voltage. As shown in FIG. 10 (c), during the period II in which 10A is on and 10C is off, the current accumulated in the reactor load 3 is circulated through the turned on 10A and the diode 10G, and the output voltage becomes zero. . Similarly, as shown in FIG. 10 (d), in the period III in which 10A is off and 10C is on, the output voltage is also reduced to zero through the turned-on 10C and the diode 10E.
Thus, the output voltage can be adjusted in the range of 0 to Ed by controlling the on / off times of 10A and 10C.
FIG. 11 shows the operation in the case of outputting a negative DC voltage, and FIG. 12 shows the operation in the case of outputting a zero voltage.

“Semiconductor Power Conversion Circuit” The Institute of Electrical Engineers of Japan, March 31, 1987, first edition, pages 81-82, section 5.2.2 “Reversible voltage chopper circuit” "Latest technical trend of PWM inverter control system" IEEJ Technical Report No. 635, May 1997, pp. 20-21, Section 3.1.2 "Application of Multi-Level"

By the way, in the voltage reversible chopper circuit, in order to control the polarity and magnitude of the output voltage, it is necessary to always switch the two semiconductor switching elements alternately. In particular, even when a zero voltage is output, as shown in FIG. 12, the two semiconductor switching elements must be operated alternately with a duty of 50%. As a result, the conventional voltage reversible chopper has a problem that switching loss due to on / off of the semiconductor switching element is large.
Further, as can be seen from the output waveforms of FIGS. 10 and 11, the output DC voltage has only two voltage levels of 0 and Ed or 0 and −Ed. Therefore, there is also a problem that the ripple component of the output current is large.

  Therefore, an object of the present invention is to reduce switching loss and reduce output current ripple.

In order to solve such a problem, according to the first aspect of the present invention, the first and second DC power supplies are connected in series, and the first and second switching circuits are connected between the positive electrode and the negative electrode of the DC power supply connected in series. An element and the first and second diodes are connected in series, and a third diode is connected between the connection point of the first and second switching elements and the connection point of the first and second DC power supplies. A first half bridge formed by connecting a fourth diode between a connection point of the first and second diodes and a connection point of the first and second DC power supplies, and the series The fifth and sixth diodes and the third and fourth switching elements are connected in series between the positive and negative electrodes of the connected DC power supply, and the connection point between the fifth and sixth diodes and the first Connect the 7th diode between the connection points of the 2nd DC power supply The third, fourth the first connection point of the switching elements, and composed of a second half-bridge formed by connecting the eighth diode between a connection point of the second DC power supply, wherein The second and third switching elements are always turned on, and the first and fourth switching elements are alternately turned on / off to obtain a three-level positive potential, and the first and fourth switching elements are obtained. The element is always turned off, and the second and third switching elements are alternately turned on / off to obtain a three-level negative potential .

In the invention of claim 2, the first and second DC power supplies are connected in series, and the first and second switching elements and the first and second diodes are connected between the positive and negative electrodes of the DC power supplies connected in series. Are connected in series, and a third diode is connected between a connection point of the first and second switching elements and a connection point of the first and second DC power supplies . A first half bridge formed by connecting a fourth diode between a connection point of two diodes and a connection point of the first and second DC power supplies, and a positive electrode and a negative electrode of the DC power supply connected in series Between the fifth and sixth diodes and the third and fourth switching elements connected in series, a connection point between the fifth and sixth diodes and a connection point between the first and second DC power supplies. A seventh diode is connected between the third and fourth switches. And a second half bridge formed by connecting an eighth diode between the connection point of the switching element and the connection point of the first and second DC power supplies, and when outputting a positive voltage, When the second and third switching elements are always turned on and a negative voltage is output, the first and fourth switching elements are always turned off, and the remaining switching elements that are not always turned on or always turned off are turned on / off. By controlling, the output voltage can be controlled and switching loss can be reduced .

In the invention of claim 3, the first and second DC power supplies are connected in series, and the first and second switching elements and the first and second diodes are connected between the positive and negative electrodes of the DC power supplies connected in series. Are connected in series, and a third diode is connected between a connection point of the first and second switching elements and a connection point of the first and second DC power supplies. A first half bridge formed by connecting a fourth diode between a connection point of two diodes and a connection point of the first and second DC power supplies, and a positive electrode and a negative electrode of the DC power supply connected in series Between the fifth and sixth diodes and the third and fourth switching elements connected in series, a connection point between the fifth and sixth diodes and a connection point between the first and second DC power supplies. A seventh diode is connected between the third and fourth switches. A second half bridge formed by connecting an eighth diode between a connection point of the element and a connection point of the first and second DC power supplies; and the second and third switching elements By turning on and turning off the first and fourth switching elements, zero voltage is output without switching, and switching loss is reduced.

According to a fourth aspect of the present invention, the first and second DC power supplies are connected in series, and the first and second switching elements and the first and second diodes are connected between the positive and negative electrodes of the DC power supplies connected in series. Are connected in series, and a third diode is connected between a connection point of the first and second switching elements and a connection point of the first and second DC power supplies. A first half bridge formed by connecting a fourth diode between a connection point of the first diode and a connection point of the first and second DC power supplies, and a positive electrode and a negative electrode of the DC power supply connected in series In addition, the fifth and sixth diodes and the third and fourth switching elements are connected in series, and the connection point of the fifth and sixth diodes and the connection point of the first and second DC power supplies A seventh diode is connected between the third and fourth switching elements. A first half carrier having an amplitude of 0 to 1 and comprising a second half bridge formed by connecting an eighth diode between a connecting point of the child and a connecting point of the first and second DC power supplies A triangular wave, a second carrier triangular wave having an amplitude of −1 to 0, a third carrier triangular wave that is 180 ° out of phase with the second carrier triangular wave, and a fourth carrier that is 180 ° out of phase with the first carrier triangular wave. The carrier triangular wave is respectively compared with an output voltage command, and each of the first, second, third, and fourth switching elements is controlled to be turned on / off.

In the invention of claim 5, the first and second DC power supplies are connected in series, and the first and second switching elements and the first diode are connected in series between the positive electrode and the negative electrode of the DC power supply connected in series. A first half bridge having a second diode connected between a connection point of the first and second switching elements and a connection point of the first and second DC power sources, and the DC power source A third diode and third and fourth switching elements are connected in series between the positive electrode and the negative electrode of the first and second connection points of the third and fourth switching elements and the first and second DC power supplies. And a second half bridge with a fourth diode connected between them, the second and third switching elements are always turned on, and the first and fourth switching elements are alternately turned on.・ Off-control and 3 level positive The first and fourth switching elements are always turned off, and the second and third switching elements are alternately turned on / off to obtain a three-level negative potential. To do.

In the invention of claim 6, the first and second DC power supplies are connected in series, and the first and second switching elements and the first diode are connected in series between the positive and negative electrodes of the DC power supplies connected in series. A first half bridge having a second diode connected between a connection point of the first and second switching elements and a connection point of the first and second DC power sources, and the DC power source A third diode and third and fourth switching elements are connected in series between the positive electrode and the negative electrode of the first and second connection points of the third and fourth switching elements and the first and second DC power supplies. When a positive voltage is output, the second and third switching elements are always turned on and a negative voltage is output. Is the first and fourth switch Always off the element, by controlling remaining on and off the switching element, wherein no off always on or always to allow control of the output voltage, and wherein possible to reduce the switching loss.

In the invention of claim 7, the first and second DC power supplies are connected in series, and the first and second switching elements and the first diode are connected in series between the positive electrode and the negative electrode of the DC power supply connected in series. A first half bridge having a second diode connected between a connection point of the first and second switching elements and a connection point of the first and second DC power sources, and the DC power source A third diode and third and fourth switching elements are connected in series between the positive electrode and the negative electrode of the first and second connection points of the third and fourth switching elements and the first and second DC power supplies. And a second half bridge with a fourth diode connected between them, and switching on by turning on the second and third switching elements and turning off the first and fourth switching elements. Output zero voltage without , Characterized in that to achieve a reduction in switching loss.

In the invention of claim 8, the first and second DC power supplies are connected in series, and the first and second switching elements and the first diode are connected in series between the positive electrode and the negative electrode of the DC power supply connected in series. A first half bridge having a second diode connected between a connection point of the first and second switching elements and a connection point of the first and second DC power sources, and the DC power source A third diode and third and fourth switching elements are connected in series between the positive electrode and the negative electrode of the first and second connection points of the third and fourth switching elements and the first and second DC power supplies. And a second half bridge having a fourth diode connected therebetween, a first carrier triangular wave with an amplitude of 0 to 1, a second carrier triangular wave with an amplitude of -1 to 0, Third phase 180 ° out of phase with carrier triangle wave A carrier triangular wave and a fourth carrier triangular wave that is 180 ° out of phase with the first carrier triangular wave are respectively compared with an output voltage command, and each of the first, second, third, and fourth switching elements is controlled to be turned on / off. It is characterized by.

According to this invention, it is possible to obtain low loss, three-level voltage reversible chopper low current ripple.
According to the invention of claim 1, 5, the output voltage 0, Ed / 2, Ed, or -Ed, since it outputs three voltage levels of -Ed / 2, 0, greatly reduces the ripple component of the output current it can.
According to the second and sixth aspects of the invention, the adjustment of the output voltage can be realized by on / off control of a part of the semiconductor switching elements, so that the switching loss is reduced as compared with the voltage reversible chopper having the same capacity as the conventional one. Can be reduced to half.

According to the third and seventh aspects of the invention, since the semiconductor switching element is not turned on / off when outputting the zero voltage, the switching loss can be made zero.
According to the fourth and eighth aspects of the present invention, a three-level gate control signal can be easily created by comparing the voltage command with the two-stage carrier signal.

FIG. 1 is a circuit diagram showing an embodiment of the present invention.
In FIG. 1, 1 is a DC power source, and 2a and 2b are voltage dividing capacitors. 10 is a three-level voltage reversible chopper according to the present invention, 3 is a load device, and 40 is a pulse width modulation (PWM) circuit for controlling the three-level voltage reversible chopper. The three-level voltage reversible chopper 10 includes semiconductor switching elements 10A to 10D made of, for example, an IGBT (insulated gate bipolar transistor), diodes 10E to 10H providing a return route, clamp diodes 10I to 10L, and the like. The semiconductor switching element is not limited to the IGBT, and a self-extinguishing semiconductor switching element such as a BJT (bipolar junction transistor) or a MOSFET (metal oxide field effect transistor) may be used.

The operation when a positive DC voltage is output will be described with reference to FIGS.
First, the semiconductor switching elements 10B and 10C are beta-on (always on), and the semiconductor switching elements 10A and 10D are on / off controlled. When both 10A and 10D are turned on in FIG. 2A, the load 3 is connected to the DC power source 1 and the output voltage becomes Ed. When 10A is turned on and 10D is turned off as shown in FIG. 2B, current flows through a path indicated by a dotted line in FIG. 2B, and the output voltage becomes Ed / 2, which is half of the DC voltage. As shown in FIG. 2C, when 10A is turned off and 10D is turned on, current flows through a path indicated by a dotted line in the figure, and the output voltage becomes Ed / 2, which is half of the DC voltage. As shown in FIG. 2D, when both 10A and 10D are turned off, current flows through a path indicated by a dotted line in the same figure, and the output voltage becomes zero.

  As can be seen from the above description, the maximum voltage applied to each semiconductor switching element is half of the DC voltage Ed. On the other hand, in the conventional voltage reversible chopper, the maximum voltage applied to each semiconductor switching element is the DC voltage Ed. When semiconductor switching elements having the same rating are used, the capacity of the present invention is higher than that of the conventional one. Is doubled. Alternatively, in order to construct a voltage reversible chopper having the same capacity as that of the present invention with a conventional voltage reversible chopper, two semiconductor switching elements must be connected in series.

As described above, when a positive voltage is output in the present invention, there are three voltage levels of 0, Ed / 2, and Ed. By controlling the on / off timing, the output voltage can be set in the range of 0 to Ed. Can be adjusted. Also, since only two of 10A, 10B, 10C, and 10D are switched on and off alternately, the semiconductor switching device is compared with the conventional voltage reversible chopper of the same capacity. Can reduce the switching loss by half.
Note that three voltage levels (-Ed, -Ed / 2 and 0) can be output by turning off the semiconductor switching elements 10A and 10D solidly (always off) and alternately turning on and off 10B and 10C. it can.

  Next, a method for generating a gate control signal of the three-level voltage reversible chopper will be described. As is apparent from the above, when the output voltage is adjusted, on / off control of the four semiconductor switching elements 10A, 10B, 10C, and 10D is required. A gate control signal generating circuit for each switching element is shown in FIG. This compares the voltage command Vref with the carrier triangular wave signals Tr1, Tr2, Tr3, Tr4 by the comparators 40A, 40B, 40C, 40D, and controls on / off of each switching element. The triangular wave signals Tr1, Tr2, Each waveform example of Tr3 and Tr4 is shown in FIG.

FIG. 4 shows a gate control signal and an output voltage waveform when a positive voltage is output.
FIG. 4A shows a case where the voltage command Vref = 0, 10B and 10C are beta-on, 10A and 10D are beta-off, and zero voltage is output without switching.
FIG. 4B shows a case where the voltage command Vref is 0 to 0.5, 10B and 10C are beta-on, 10A and 10D are turned on / off, and a pulse voltage of 0 to Ed / 2 is output.

FIG. 4C shows a case where the voltage command Vref is 0.5 to 1.0, 10B and 10C are beta-on, 10A and 10D are turned on / off, and a pulse voltage of Ed / 2 to Ed is output. is there.
As described above, the output voltage is proportional to the voltage command Vref, and three voltage levels of 0, Ed / 2, and Ed can be output by adjusting Vref.
FIG. 5 shows a gate control signal and an output voltage waveform when a negative voltage is output. It is possible to adjust the output to three voltage levels of -Ed, -Ed / 2, and 0 by solidly turning off 10A and 10D and alternately turning on and off 10B and 10C.

FIG. 6 shows another embodiment of the present invention.
This is different from that shown in FIG. 1 in that the series circuit of diodes 10E and 10F is only 10E, the series circuit of diodes 10G and 10H is only 10G, and the clamp diodes 10J and 10K are omitted. is there.

In this way, the same function as in FIG. 1 can be provided, and when a positive DC voltage is output, the description in FIGS. 2A to 2D can be similarly applied here, and will be described as FIGS. 7A to 7D. be able to. It can be seen that the dotted line paths are almost the same in FIGS.
In addition, when outputting a negative DC voltage, it becomes like FIG. 8A-8D, but conversely this description is applicable also when outputting a negative DC voltage in FIG. Similarly, the description of FIGS. 3, 4 and 5 with respect to FIG. 1 can be applied to the case of FIG. 6 in the same manner, and the functions, operations and effects are almost the same.

Circuit diagram showing an embodiment of the present invention Explanatory drawing of the 1st electric current path in the case of outputting a positive voltage in FIG. Explanatory diagram of the second current path when outputting a positive voltage in FIG. Explanatory diagram of the third current path when outputting a positive voltage in FIG. Explanatory diagram of the fourth current path when outputting a positive voltage in FIG. The circuit configuration and carrier signal waveform diagram for generating the gate control signal in FIG. Figure 1 shows the gate pulse and output voltage waveform when a positive voltage is output in Fig. 1. Figure 1 shows the gate pulse and output voltage waveform when a negative voltage is output in Fig. 1. Circuit diagram showing another embodiment of the present invention Explanatory diagram of the first current path when outputting a positive voltage in FIG. Explanatory diagram of the second current path when outputting a positive voltage in FIG. Explanatory diagram of the third current path when outputting a positive voltage in FIG. Explanatory diagram of the fourth current path when outputting a positive voltage in FIG. Explanatory drawing of the 1st electric current path in the case of outputting a negative voltage in FIG. Explanatory drawing of the 2nd electric current path in the case of outputting a negative voltage in FIG. Explanatory diagram of the third current path when outputting a negative voltage in FIG. Explanatory diagram of the fourth current path when outputting a negative voltage in FIG. Circuit diagram showing a conventional example of a voltage reversible chopper FIG. 9 is a diagram illustrating the operation when a positive DC voltage is output. FIG. 9 is a diagram for explaining the operation when a negative DC voltage is output. Explanation of operation when outputting zero voltage in FIG.

DESCRIPTION OF SYMBOLS 1 ... DC power supply, 2a, 2b ... Voltage dividing capacitor, 10 ... 3 level voltage reversible chopper, 10A, 10B, 10C, 10D ... Semiconductor switching element, 10E, 10F, 10G, 10H ... Diode, 10I, 10J, 10K, 10L ... clamping diodes, 40 ... pulse width modulation (PWM) circuit, 40A, 40B, 40C, 40D ... comparator, Vref ... voltage command, Tr1 to Tr4 ... triangular wave signal.

Claims (8)

The first and second DC power supplies are connected in series, and the first and second switching elements and the first and second diodes are connected in series between the positive and negative electrodes of the DC power supplies connected in series. A third diode is connected between a connection point of the first and second switching elements and a connection point of the first and second DC power supplies, and a connection point of the first and second diodes. A first half bridge formed by connecting a fourth diode between connection points of the first and second DC power supplies, and fifth and sixth terminals between the positive and negative electrodes of the DC power supplies connected in series. The diode and the third and fourth switching elements are connected in series, and a seventh point is connected between the connection point of the fifth and sixth diodes and the connection point of the first and second DC power supplies. A diode is connected, and the connection point of the third and fourth switching elements and the 1, and composed of a second half-bridge formed by connecting the eighth diode between a connection point of the second DC power supply,
The second and third switching elements are always turned on, and the first and fourth switching elements are alternately turned on / off to obtain a three-level positive potential. A three-level voltage reversible chopper device characterized in that a switching element is always turned off, and the second and third switching elements are alternately turned on / off to obtain a three-level negative potential . The first and second DC power supplies are connected in series, and the first and second switching elements and the first and second diodes are connected in series between the positive electrode and the negative electrode of the DC power supply connected in series. A third diode is connected between a connection point of the first and second switching elements and a connection point of the first and second DC power supplies, and a connection point of the first and second diodes. A first half bridge formed by connecting a fourth diode between connection points of the first and second DC power supplies, and fifth and sixth terminals between the positive and negative electrodes of the DC power supplies connected in series. The diode and the third and fourth switching elements are connected in series, and a seventh point is connected between the connection point of the fifth and sixth diodes and the connection point of the first and second DC power supplies. A diode is connected, and the connection point of the third and fourth switching elements and the A second half bridge formed by connecting an eighth diode between the connection points of the first and second DC power supplies ;
When outputting a positive voltage, the second and third switching elements are always turned on. When outputting a negative voltage, the first and fourth switching elements are always turned off, and the always on or always off. A three-level voltage reversible chopper device characterized in that output voltage can be controlled and switching loss is reduced by controlling on / off of the remaining switching elements . The first and second DC power supplies are connected in series, and the first and second switching elements and the first and second diodes are connected in series between the positive and negative electrodes of the DC power supplies connected in series. A third diode is connected between a connection point of the first and second switching elements and a connection point of the first and second DC power supplies, and a connection point of the first and second diodes. A first half bridge formed by connecting a fourth diode between connection points of the first and second DC power supplies, and fifth and sixth terminals between the positive and negative electrodes of the DC power supplies connected in series. The diode and the third and fourth switching elements are connected in series, and a seventh point is connected between the connection point of the fifth and sixth diodes and the connection point of the first and second DC power supplies. A diode is connected, and the connection point of the third and fourth switching elements and the 1, and composed of a second half-bridge formed by connecting the eighth diode between a connection point of the second DC power supply,
By turning on the second and third switching elements and turning off the first and fourth switching elements, zero voltage is output without switching, and switching loss is reduced. Level voltage reversible chopper device. The first and second DC power supplies are connected in series, and the first and second switching elements and the first and second diodes are connected in series between the positive and negative electrodes of the DC power supplies connected in series. A third diode is connected between a connection point of the first and second switching elements and a connection point of the first and second DC power supplies, and a connection point of the first and second diodes. A first half bridge formed by connecting a fourth diode between connection points of the first and second DC power supplies, and fifth and sixth terminals between the positive and negative electrodes of the DC power supplies connected in series. The diode and the third and fourth switching elements are connected in series, and a seventh point is connected between the connection point of the fifth and sixth diodes and the connection point of the first and second DC power supplies. A diode is connected, and the connection point of the third and fourth switching elements and the 1, and composed of a second half-bridge formed by connecting the eighth diode between a connection point of the second DC power supply,
A first carrier triangular wave having an amplitude of 0 to 1, a second carrier triangular wave having an amplitude of −1 to 0, a third carrier triangular wave that is 180 ° out of phase with the second carrier triangular wave, and the first carrier triangular wave And a fourth carrier triangular wave that is 180 ° out of phase with the output voltage command, and the on / off control of each of the first, second, third, and fourth switching elements is performed. apparatus. The first and second DC power supplies are connected in series, and the first and second switching elements and the first diode are connected in series between the positive and negative electrodes of the DC power supplies connected in series. , A first half bridge in which a second diode is connected between the connection point of the second switching element and the connection point of the first and second DC power supplies, and the first half bridge between the positive electrode and the negative electrode of the DC power supply. The third diode and the third and fourth switching elements are connected in series, and a fourth point is connected between the connection point of the third and fourth switching elements and the connection point of the first and second DC power supplies. A second half bridge connected with a diode,
The second and third switching elements are always turned on, and the first and fourth switching elements are alternately turned on / off to obtain a three-level positive potential. A three-level voltage reversible chopper device characterized in that a switching element is always turned off, and the second and third switching elements are alternately turned on / off to obtain a three-level negative potential . The first and second DC power supplies are connected in series, and the first and second switching elements and the first diode are connected in series between the positive and negative electrodes of the DC power supplies connected in series. , A first half bridge in which a second diode is connected between the connection point of the second switching element and the connection point of the first and second DC power supplies, and the first half bridge between the positive electrode and the negative electrode of the DC power supply. The third diode and the third and fourth switching elements are connected in series, and a fourth point is connected between the connection point of the third and fourth switching elements and the connection point of the first and second DC power supplies. A second half bridge connected with a diode,
When outputting a positive voltage, the second and third switching elements are always turned on. When outputting a negative voltage, the first and fourth switching elements are always turned off, and the always on or always off. A three-level voltage reversible chopper device characterized in that output voltage can be controlled and switching loss is reduced by controlling on / off of the remaining switching elements . The first and second DC power supplies are connected in series, and the first and second switching elements and the first diode are connected in series between the positive and negative electrodes of the DC power supplies connected in series. , A first half bridge in which a second diode is connected between the connection point of the second switching element and the connection point of the first and second DC power supplies, and the first half bridge between the positive electrode and the negative electrode of the DC power supply. The third diode and the third and fourth switching elements are connected in series, and a fourth point is connected between the connection point of the third and fourth switching elements and the connection point of the first and second DC power supplies. A second half bridge connected with a diode,
By turning on the second and third switching elements and turning off the first and fourth switching elements, zero voltage is output without switching, and switching loss is reduced. Level voltage reversible chopper device. The first and second DC power supplies are connected in series, and the first and second switching elements and the first diode are connected in series between the positive and negative electrodes of the DC power supplies connected in series. , A first half bridge in which a second diode is connected between the connection point of the second switching element and the connection point of the first and second DC power supplies, and the first half bridge between the positive electrode and the negative electrode of the DC power supply. The third diode and the third and fourth switching elements are connected in series, and a fourth point is connected between the connection point of the third and fourth switching elements and the connection point of the first and second DC power supplies. A second half bridge connected with a diode,
A first carrier triangular wave having an amplitude of 0 to 1, a second carrier triangular wave having an amplitude of −1 to 0, a third carrier triangular wave that is 180 ° out of phase with the second carrier triangular wave, and the first carrier triangular wave And a fourth carrier triangular wave that is 180 ° out of phase with the output voltage command, and the on / off control of each of the first, second, third, and fourth switching elements is performed. apparatus.

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