TWI802370B - Phase switching control method for matrix converter - Google Patents

Abstract

A phase switching control method for a matrix converter includes the following steps. Firstly, a second half cycle timing of a second switching mode corresponding to the half period to the full period of a second input control period is extracted from a second switching mode timing sequence. Next, a pulse width of the second half-cycle timing of the second switching mode is extended to twice to generate a transition switching mode timing. Then, when the matrix converter enters the transition input control period from the first input control period, the matrix converter is controlled to perform phase switching according to the transition switching mode timing sequence. Finally, after the matrix converter completes the phase switching according to the transition switching mode timing, the matrix converter is controlled to perform phase switching according to the second switching mode timing.

Description

Phase Switching Control Method of Matrix Converter

The present invention relates to a control method of a matrix converter, in particular to a phase switching control method of a matrix converter.

Please refer to the first figure, which shows the circuit structure diagram of the prior art matrix converter. As shown in the first figure, a matrix converter MC includes three input power side three-phase A, B and C, three output load side three-phase a, b and c and three-phase switch module TM, and the three-phase switch The module TM includes nine bidirectional switches SAa, SAb, SAc, SBa, SBb, SBc, SCa, SCb, and SCc. The three phases A, B, and C of the three input power sides are respectively connected to an AC power supply PS, and the three The three phases a, b and c on the output load side are respectively connected to a load Load.

Nine bidirectional switches SAa, SAb, SAc, SBa, SBb, SBc, SCa, SCb and SCc are respectively set on three input power side three phases A, B and C and three output load sides three phases a, b and c between three phases A, B and C on the input power side and three phases a, b and c on the three output load sides to control the three-phase conduction relationship.

Please continue to refer to the second figure and the third figure. The second figure is a schematic diagram showing that the triangular carrier corresponding to the change of the switching mode caused by the change of the input current of the matrix converter in the prior art corresponds to the switch-on timing interval of the nine bidirectional switches; the third figure It is a schematic diagram showing the switching states of nine bidirectional switches modulated by a triangular carrier wave in a prior art matrix converter.

As shown in the first figure to the third figure, the nine bidirectional switches SAa, SAb, SAc, SBa, SBb, SBc, SCa, SCb and SCc respectively correspond to nine switch turn-on timing intervals Aa, Ab, Ac, Ba, Bb , Bc, Ca, Cb, and Cc, and these switch opening time sequence intervals Aa, Ab, Ac, Ba, Bb, Bc, Ca, Cb, and Cc are controlled by the first switching mode timing during the first input control period M1 , and then make the three-phase switch module TM use the triangular carrier wave W1 and the PWM switch DUTY control amount Da to Df to modulate the switching state, where the triangular carrier wave W1 refers to the carrier wave from a cycle start time T0 to a full cycle time Ts The shape is triangular, and the cycle start time T0 is also equivalent to the full cycle time Ts of the previous cycle.

In addition, since the first switching mode sequence corresponding to the first input control cycle M1 is at the full cycle time Ts, it corresponds to the switch-on sequence intervals Aa, Ab, and Ac, which means that in the first input control cycle M1 and the full cycle time At Ts, only the bidirectional switches SAa, SAb, and SAc are in the on-state, but the second switching mode sequence corresponding to the second input control cycle M2 is at the cycle start time T0 (because it is a cycle of each cycle, so the whole cycle The time Ts is equivalent to the start time T0 of the next cycle, which corresponds to the switch-on sequence intervals Ca, Cb and Cc. Therefore, when the three-phase switch module TM is switched from the first input control cycle M1 to During the second input control cycle M2, the three-phase switch module TM is a switching state modulated by using the triangular carrier wave W2 and the PWM switch DUTY control quantities Da to Df, and when the triangular carrier wave W1 is switched to the triangular carrier wave W2, the bidirectional switch SAa , SAb, and SAc will switch to bidirectional switches SCa, SCb, and SCc respectively at the same time, resulting in relatively large switching noise and consumption, which is a heavy burden on the entire matrix converter MC.

In view of the fact that in the prior art, the existing matrix converter will use the same and fixed triangular carrier wave for the modulation of the switch state in each control cycle based on the principle of PWM carrier switching, but it is very likely because of the change of the three-phase current of the input power supply However, switching to the switch control method with different timing modes, and at the same time when the mode is switched, it is often encountered that the three-phase switch module switches from one phase to another at the same time, resulting in a large switching noise and consumption Therefore, the main purpose of the present invention is to provide a phase switching control method of a matrix converter, which can generate a transitional switching mode sequence from the existing switching mode sequence, so that the three-phase switch module is smoother when switching modes.

In order to solve the problems of the prior art, the necessary technical means adopted by the present invention is to provide a phase switching control method of a matrix converter, which is used for a matrix converter to perform phase switching according to a first switching mode timing sequence. When the input control cycle is switched to a second input control cycle for phase switching according to a second switching mode sequence, a transitional input control cycle is inserted between the first input control cycle and the second input control cycle, and the first input control cycle is inserted between the first input control cycle and the second input control cycle. The switch state of the three-phase switch module of the full cycle time of the input control cycle is the same as the switch state of the three-phase switch module of the half cycle time of the second input control cycle, and the first input control cycle, the transition input The control cycle is equal to the carrier width of the second input control cycle, and the phase switching control method of the matrix converter includes the following steps (A) to (D).

Step (A) is to extract from the second switching mode timing a second switching mode second half cycle timing corresponding to half cycle to full cycle of the second input control cycle.

Step (B) is to double the carrier width of the second half cycle timing of the second switching mode to generate a transition switching mode timing.

Step (C) is to control the matrix converter to perform phase switching according to the timing of the transition switching mode when the matrix converter enters the transition input control period from the first input control period.

Step (D) is to control the matrix converter to perform phase switching according to the timing of the second switching mode after the phase switching of the matrix converter according to the timing of the transition switching mode is completed.

In one of the subsidiary technical means derived from the above necessary technical means, step (C) when the matrix converter enters the transition input control period from the first input control period, a triangular carrier wave used by the matrix converter is continuously A sawtooth wave.

Preferably, after the step (D) is completed by performing phase switching according to the timing of the transition switching mode, the sawtooth wave used by the matrix converter is followed by another triangular carrier wave.

As mentioned above, the phase switching control method of the matrix converter of the present invention can effectively prevent the three-phase currents from being switched at the same time by inserting a transitional input control cycle between the first input control cycle and the second input control cycle. Furthermore, the problems of large switching noise and consumption are avoided, so as to make the switching mode of the three-phase switch module more smooth.

The specific embodiments adopted by the present invention will be further described by the following embodiments and drawings.

Please refer to the first figure to the seventh figure. The fourth figure shows the phase switching control method of the matrix converter provided by the preferred embodiment of the present invention. From the second figure, the second half-cycle sequence after the input current changes Schematic diagram of the complete cycle timing of the switching mode; the fifth figure shows that the phase switching control method of the matrix converter provided by the preferred embodiment of the present invention increases the timing of the second half cycle of the second switching mode proportionally to one cycle to form the timing of the transitional switching mode The schematic diagram; the sixth figure is a schematic diagram showing that the phase switching control method of the matrix converter provided by the preferred embodiment of the present invention inserts the transition switching mode sequence into the first input control mode cycle and the second input control mode cycle; the seventh The figure is a flow chart showing the steps of the phase switching control method of the matrix converter provided by the preferred embodiment of the present invention.

As shown in the first figure to the seventh figure, a phase switching control method of a matrix converter is used for switching a matrix converter MC in a first input control period M1 for phase switching according to a first switching mode sequence When it is a second input control period M2 (equivalent to the second figure) for phase switching according to a second switching mode sequence, a transitional input control period is inserted between the first input control period M1 and the second input control period M2 Mt, the switch state of the three-phase switch module TM in the full cycle time Ts of the first input control cycle M1 is the same as the switch state of the three-phase switch module TM in the half cycle time Ts/2 of the second input control cycle M2 ( That is, the switching state of the three-phase switch module TM in the first input control cycle M1 in the full cycle time Ts in the second figure corresponds to the switch opening time sequence intervals Aa, Ab and Ac, and the half cycle of the second input control cycle M2 The switching state of the three-phase switch module TM at time Ts/2 is also corresponding to the switch opening time sequence intervals Aa, Ab and Ac), and the first input control period M1, the transition input control period Mt and the second input control period M2 The carrier widths are all equal.

Based on the above, the phase switching control method of the matrix converter of the present invention includes the following steps S101 to S104.

Firstly, step S101 is to extract a second half-period sequence of the second switching mode corresponding to half-cycle to full-cycle of the second input control cycle M2 from the second switching-mode sequence. Wherein, the second switching mode timing is the three-phase arrangement sequence of the switch opening timing intervals Aa, Ab, Ac, Ba, Bb, Bc, Ca, Cb and Cc corresponding to the second input control cycle M2, and the second input control The period M2 refers to a period in which the cycle is performed at the second switching mode sequence. In addition, the timing of the second half cycle of the second switching mode is the part from the middle of the switch-on timing intervals Aa, Ab, and Ac to the switch-on timing intervals Ca, Cb, and Cc in the second input control cycle, which is equivalent to the part in the fourth figure The timing sequence of the second switching mode included in the second input control period M2 corresponds to the part of the second half period (half period time Ts/2 to full period time Ts).

Step S102 is to extend the carrier width of the second half-cycle timing of the second switching mode to twice to generate a transitional switching mode timing; wherein, since the second half-cycle timing of the second switching mode is the part corresponding to the second half-cycle of the second switching mode timing, Therefore, the transition switching mode timing generated by extending the carrier width of the second half-cycle timing of the second switching mode to twice corresponds to a full full cycle.

Step S103 is to control the matrix converter MC to perform phase switching according to the sequence of the transition switching mode when the matrix converter MC enters the transition input control period Mt from the first input control period M1. Wherein, when the matrix converter MC enters the transitional input control period Mt from the first input control period M1, the triangular carrier wave W1 used by the matrix converter MC is followed by a sawtooth wave Wt.

Step S104 is to control the matrix converter MC to perform phase switching according to the second switching mode sequence after the matrix converter MC completes the phase switching according to the transition switching mode sequence.

Please continue to refer to the eighth figure, which is a schematic diagram showing that when the input current of the matrix converter of the phase switching control method of the matrix converter provided by the preferred embodiment of the present invention changes, the change of the switching mode causes the triangular carrier wave to correspond to nine bidirectional states . As shown in the first figure to the eighth figure, in the first input control period M1, the nine bidirectional switches SAa, SAb, SAc, SBa, SBb, SBc, SCa, SCb and SCc are turned on or off to form a triangular carrier wave W1 , and when the matrix converter MC receives a mode switching signal MS, through steps S101 to S104 of the present invention, the first input control period M1 will be switched to the transition input control period Mt first, and then switched to the second input control period period M2, whereby the nine bidirectional switches SAa, SAb, SAc, SBa, SBb, SBc, SCa, SCb and SCc do not need to be switched when the first input control period M1 is first switched to the transitional input control period Mt action, and when the transition input control period Mt is switched to the second input control period M2, the nine bidirectional switches SAa, SAb, SAc, SBa, SBb, SBc, SCa, SCb and SCc do not need to perform switching actions, and make The sawtooth wave Wt continues the original triangular carrier wave W2. Compared with the prior art, when the first input control period M1 is switched to the second input control period M2, there will be a large switching noise and consumption due to the simultaneous switching of the three-phase currents, the phase switching of the matrix converter of the present invention The control method inserts a transitional input control period Mt between the first input control period M1 and the second input control period M2, which can indeed effectively prevent the three-phase currents from being switched at the same time, thereby avoiding the generation of large switching noise and The problem of consumption is used to make the three-phase switch module TM smoother when switching modes.

In addition, in practice, according to the Space Vector approach, there will be 36 combinations of the 6 input intervals of the matrix converter MC corresponding to the 6 output intervals, but because half of them are repeated, there will actually be There are 18 effective switch change combinations, and the first switching mode sequence of the first input control period M1 in this embodiment is only one of the switch change combinations, while the second switch mode sequence of the second input control period M2 is another The combination of switches changes, so in practice, the phase switching control method of the matrix converter of the present invention can be applied to the switching between the 18 switching modes.

It should be added that in the second, third, fourth, fifth, sixth and eighth figures, the physical quantities of the abscissa and ordinate of the triangular carrier wave W1 and W2 and the sawtooth wave Wt are respectively is time and voltage, and the abscissa of the nine bidirectional switches SAa, SAb, SAc, SBa, SBb, SBc, SCa, SCb, and SCc in the eighth figure is also time, while the ordinate is to use the height to represent on and off. close.

Through the above detailed description of the preferred embodiments, it is hoped that the characteristics and spirit of the present invention can be described more clearly, and the scope of the present invention is not limited by the preferred embodiments disclosed above. On the contrary, the intention is to cover various changes and equivalent arrangements within the scope of the claimed patent scope of the present invention.

MC: matrix converter A, B, C: three-phase input power side a, b, c: output load side three-phase TM: Three-phase switch module PS: AC power Load: load SAa, SAb, SAc, SBa, SBb, SBc, SCa, SCb, SCc: bidirectional switch Aa, Ab, Ac, Ba, Bb, Bc, Ca, Cb, Cc: switch open timing interval M1: first input control period M2: Second input control period Mt: transition input control period MS: mode switching signal W1: triangle carrier W2: triangle carrier Wt: sawtooth wave T0: cycle start time Ts: full cycle time Ts/2: half cycle time S101-S104: Steps Da, Db, Dc, Dd, De, Df: PWM switch DUTY control value

The first figure shows the circuit structure diagram of the prior art matrix converter; The second figure is a schematic diagram showing that the triangular carrier wave corresponding to the change of the switching mode caused by the change of the input current of the matrix converter of the prior art corresponds to the switch-on timing interval of the nine bidirectional switches; The third figure is a schematic diagram showing the switch state of nine bidirectional switches modulated by the matrix converter of the prior art through the triangular carrier wave; The fourth figure is a schematic diagram showing the complete cycle timing of the second switching mode of the phase switching control method of the matrix converter provided by the preferred embodiment of the present invention, which is extracted from the second figure after the half cycle timing after the input current changes; The fifth figure is a schematic diagram showing that the phase switching control method of the matrix converter provided by the preferred embodiment of the present invention increases the timing sequence of the second half cycle of the second switching mode proportionally to one cycle to form the timing sequence of the transition switching mode; The sixth figure is a schematic diagram showing that the phase switching control method of the matrix converter provided by the preferred embodiment of the present invention inserts the transition switching mode sequence into the first input control mode cycle and the second input control mode cycle; The seventh figure is a flow chart showing the steps of the phase switching control method of the matrix converter provided by the preferred embodiment of the present invention; and The eighth figure is a schematic diagram showing that when the input current of the matrix converter of the phase switching control method of the matrix converter provided by the preferred embodiment of the present invention changes, the change of the switching mode causes the triangular carrier to correspond to nine bidirectional states.

Aa, Ab, Ac, Ba, Bb, Bc, Ca, Cb, Cc: switch open timing interval

M1: first input control cycle

M2: Second input control cycle

Mt: transition input control period

W1: triangle carrier

W2: triangle carrier

Wt: sawtooth wave

Ts: full cycle time

Da, Db, Dc, Dd, De, Df: PWM switch DUTY control value

Claims (3)

A phase switching control method of a matrix converter, which is used for a matrix converter to switch from a first input control cycle that performs phase switching according to a first switching mode timing to a phase switching based on a second switching mode timing During the second input control cycle, a transitional input control cycle is inserted between the first input control cycle and the second input control cycle, and the switching state of the three-phase switch module in the full cycle time of the first input control cycle is The switch state of the three-phase switch module is the same as the half cycle time of the second input control cycle, and the carrier width of the first input control cycle, the transition input control cycle and the second input control cycle are all equal, the matrix The phase switching control method of the converter includes the following steps: (A) extracting from the second switching mode timing a second switching mode second half cycle timing corresponding to the half cycle to the full cycle of the second input control cycle; (B) Extending the carrier width of the second half cycle timing of the second switching mode to twice to generate a transition switching mode timing; (C) when the matrix converter enters the transition input control period from the first input control period, controlling the matrix converter to perform phase switching according to the transition switching mode sequence; and (D) After the phase switching of the matrix converter according to the transition switching mode sequence is completed, controlling the matrix converter to perform phase switching according to the second switching mode sequence. The phase switching control method of a matrix converter as described in Claim 1, wherein in step (C) when the matrix converter enters the transition input control period from the first input control period, one of the The triangular carrier is followed by a sawtooth wave. The phase switching control method of the matrix converter as described in claim 2, wherein, after the step (D) is completed after the phase switching of the matrix converter according to the timing of the transition switching mode, the sawtooth wave used by the matrix converter is followed by another triangular carrier.

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