Phase power supply path switching circuit

Abstract

A phase power supply path switching circuit comprises a three-phase input end, a three-phase output end, a matrix switch unit, a detection unit and a control unit. The matrix switch unit includes a plurality of bidirectional switches coupled between the three-phase input terminal and the three-phase output terminal. The detection unit is coupled to and detects voltages of the first phase line, the second phase line and the third phase line. The control unit is coupled to the detection unit and the matrix switch unit to control the two-way switches to switch the first phase power path and the second phase power path in response to detecting that a first line voltage between the first phase line and the second phase line is a zero point and a second line voltage between the second phase line and the third phase line is in a polarity half cycle.

Description

Technical Field

[0001] The invention relates to a switching control circuit, and in particular to a phase power path switching circuit. Background Art

[0002] The three-phase power supply can be supplied to different loads respectively. However, if the load of one phase of the power supply is too heavy and the power consumption is too large, the power distribution equipment of the phase of the power supply will increase the loss and reduce the service life. However, there is currently no solution that can perform load balancing. Summary of the invention

[0003] The present invention provides a phase power path switching circuit, which receives a three-phase power supply from a power supply end, and includes a three-phase input end, a three-phase output end, a matrix switch unit, a detection unit and a control unit. The three-phase input end includes a first phase input end, a second phase input end and a third phase input end, which respectively receive the three-phase power supply from the power supply end. The three-phase output end includes a first phase output end, a second phase output end and a third phase output end. The matrix switch unit includes a plurality of bidirectional switches. Each bidirectional switch is coupled between one of the three-phase input ends and one of the three-phase output ends, wherein the first phase input end and the first phase output end are coupled via a first bidirectional switch among the bidirectional switches to form a first phase line, and the second phase input end and the second phase output end are coupled via a second bidirectional switch among the bidirectional switches to form a second phase line. The detection unit is configured to detect the first phase line, the second phase line and a third phase line, and the third phase line is coupled between the third phase input end and the third phase output end. The control unit is coupled to the detection unit and the matrix switch unit, and is configured to, after receiving a switching signal, in response to detecting that a first line voltage between the first phase line and the second phase line is zero and a second line voltage between the second phase line and the third phase line is within a polarity half cycle, sequentially execute: (a) closing a first conduction direction of the first bidirectional switch and the second bidirectional switch, wherein the first conduction direction is opposite to the current direction of the polarity half cycle; (b) opening a second conduction direction of a third bidirectional switch and a fourth bidirectional switch among the bidirectional switches, wherein the second conduction direction is the same as the current direction of the polarity half cycle, wherein the third bidirectional switch is coupled between the second phase input terminal and the first phase output terminal, and the fourth bidirectional switch is coupled between the first phase input terminal and the second phase output terminal; (c) closing the second conduction direction of the first bidirectional switch and the second bidirectional switch; and (d) opening the first conduction direction of the third bidirectional switch and the fourth bidirectional switch.

[0004] According to some embodiments of the present invention, the phase power path switching circuit only needs to use voltage detection without current detection, and does not need to consider the phase sequence of the three-phase power supply. The switching time point can be determined by detecting the two-line voltage, and is applicable to a variety of connection architectures between the power supply end and the load end, with plug-and-play convenience and versatility. After switching the phase power path, the loads coupled to the two-phase lines are exchanged with each other, so that the load balancing effect can be achieved. In addition, through the switch switching sequence of the aforementioned steps, the short circuit of the power supply end and the open circuit of the load end can be avoided during the path switching process. And the use of a bidirectional switch can have the effects of fast switching and zero current switching (flexible switching).

[0005] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments, but is not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 FIG. 4 is a block diagram of a phase power path switching circuit according to some embodiments of the present invention.

[0007] Figure 2 2 is a circuit diagram of a phase power path switching circuit according to the first and second embodiments of the present invention.

[0008] Figure 3 Schematic diagram of phase voltage and line voltage of a three-phase power supply according to some embodiments of the present invention.

[0009] Figure 4 FIG. 4 is a partial schematic diagram of a matrix switch unit according to a first embodiment of the present invention.

[0010] Figure 5 FIG. 4 is a flow chart of phase power path switching according to some embodiments of the present invention.

[0011] Figure 6 FIG. 4 is a timing diagram of the phase power path switching process according to the first embodiment of the present invention.

[0012] Figure 7 FIG. 1 is a schematic diagram of a partial circuit state of a matrix switch unit according to a first embodiment of the present invention (I).

[0013] Figure 8 FIG. 2 is a schematic diagram of a partial circuit state of a matrix switch unit according to the first embodiment of the present invention (II).

[0014] Fig. 9 FIG. 3 is a schematic diagram of a partial circuit state of a matrix switch unit according to the first embodiment of the present invention. FIG.

[0015] Fig.10 FIG4 is a schematic diagram of a partial circuit state of a matrix switch unit according to the first embodiment of the present invention.

[0016] Fig.11FIG. 4 is a partial schematic diagram of a matrix switch unit according to a second embodiment of the present invention.

[0017] Fig.12 2 is a circuit diagram of a phase power path switching circuit according to the third and fourth embodiments of the present invention.

[0018] Fig.13 FIG. 4 is a partial schematic diagram of a matrix switch unit according to a third embodiment of the present invention.

[0019] Fig.14 FIG. 4 is a partial schematic diagram of a matrix switch unit according to a fourth embodiment of the present invention.

[0020] Fig.15 FIG. 4 is a circuit diagram of a phase power path switching circuit according to a fifth embodiment of the present invention.

[0021] Fig.16 FIG. 4 is a circuit diagram of a phase power path switching circuit according to a ninth embodiment of the present invention.

[0022] Fig.17 FIG. 1 is a circuit diagram of a phase power path switching circuit according to a seventeenth embodiment of the present invention.

[0023] Among them, the reference numerals

[0024] 10: Phase power path switching circuit

[0025] 11: Three-phase input terminal

[0026] 12: Three-phase output terminal

[0027] 13: Matrix switch unit

[0028] 14: Detection Unit

[0029] 15: Control unit

[0030] 151: Controller

[0031] 152: Gate drive circuit

[0032] 20: Power supply terminal

[0033] 21: Single-phase power supply

[0034] 30: Load end

[0035] 31: Load

[0036] 41: First switch

[0037] 42: Second switch

[0038] R: First phase input terminal

[0039] S: Second phase input terminal

[0040] T: The third phase input terminal

[0041] U: first phase output terminal

[0042] V: Second phase output terminal

[0043] W: third phase output terminal

[0044] G: Switch Group

[0045] Q: Bidirectional switch

[0046] Q RU :Two-way switch

[0047] Q SU :Two-way switch

[0048] Q TU :Two-way switch

[0049] Q RV :Two-way switch

[0050] Q SV :Two-way switch

[0051] Q TV :Two-way switch

[0052] Q RW :Two-way switch

[0053] Q SW :Two-way switch

[0054] Q TW :Two-way switch

[0055] Vph1, Vph2, Vph3: Phase voltage

[0056] V 12 ,V 23 ,V 31 :Line voltage

[0057] V UV :Voltage

[0058] V VW :Voltage

[0059] V WU :Voltage

[0060] p1,p2: time point

[0061] t1,t2,t3,t4: time

[0062] S51~S57: Steps DETAILED DESCRIPTION

[0063] The structural principle and working principle of the present invention are described in detail below in conjunction with the accompanying drawings:

[0064] As used herein, "coupled" refers to two or more elements making "direct" physical or electrical contact with each other, or "indirect" physical or electrical contact with each other, or may refer to two or more elements acting on each other. As used herein, the terms "first" and "second" are used to distinguish the elements referred to, but are not used to sort or limit the differences of the elements referred to, and are not used to limit the scope of the present invention.

[0065] Reference Figure 1 , is a block diagram of a phase power path switching circuit 10 according to some embodiments of the present invention. The phase power path switching circuit 10 is coupled between a power source terminal 20 and a load terminal 30. The phase power path switching circuit 10 receives a three-phase power provided by the power source terminal 20 and provides the three-phase power to the load terminal 30.

[0066] The phase power path switching circuit 10 includes a three-phase input terminal 11, a three-phase output terminal 12, a matrix switch unit 13, a detection unit 14 and a control unit 15. The three-phase input terminal 11 includes a first phase input terminal R, a second phase input terminal S and a third phase input terminal T, so as to couple with the power terminal 20 and respectively receive the three-phase power of the power terminal 20. The three-phase output terminal 12 includes a first phase output terminal U, a second phase output terminal V and a third phase output terminal W, so as to couple with the load terminal 30 and respectively output the three-phase power to the load terminal 30. The first phase input terminal R, the second phase input terminal S and the third phase input terminal T are respectively coupled to the first phase output terminal U, the second phase output terminal V and the third phase output terminal W through the matrix switch unit 13 to form a first phase line, a second phase line and a third phase line respectively. The first phase line is coupled between the first phase input terminal R and the first phase output terminal U; the second phase line is coupled between the second phase input terminal S and the second phase output terminal V; and the third phase line is coupled between the third phase input terminal T and the third phase output terminal W. The detection unit 14 is coupled to the first phase line, the second phase line and the third phase line. The detection unit 14 has a voltage detection circuit to detect the voltages of the first phase line, the second phase line and the third phase line. The control unit 15 is coupled to the detection unit 14 and the matrix switch unit 13, so that after receiving the switching signal, it responds to the detection result of the detection unit 14 to control the matrix switch unit 13 to achieve the purpose of switching the phase power path. The operation process will be described in detail later.

[0067] The switching phase power supply path refers to the switching of two phase power supply paths with each other. Specifically, the X-phase input terminal of the X-phase line is originally coupled to the X-phase output terminal, and the Y-phase input terminal of the Y-phase line is originally coupled to the Y-phase output terminal. After the phase power supply path is switched, the X-phase input terminal is coupled to the Y-phase output terminal, and the Y-phase input terminal is coupled to the X-phase output terminal. This article uses the switching between the first phase line and the second phase line to illustrate the process of switching the phase power supply path. It can be understood that the same operation method can be applied to the situation where the second phase line and the third phase line are switched with each other or the situation where the third phase line and the first phase line are switched with each other, which will not be repeated in this article.

[0068] In some embodiments, the switching signal is generated by a person operating a trigger switch coupled to the control unit 15 when a switching demand is found. In other embodiments, an electronic device executes an analysis logic, and when the analysis logic finds that a switching condition is met, the switching signal is transmitted to the control unit 15. The analysis logic can analyze the three-phase load power, and when the three-phase load power is unbalanced, the switching condition is determined to be met. After switching the phase power path, the loads coupled to the two-phase lines are exchanged with each other, so that the load balancing effect can be achieved.

[0069] Reference Figure 2 , is a circuit diagram of the phase power path switching circuit 10 of the first and second embodiments of the present invention. The matrix switch unit 13 includes a plurality of bidirectional switches Q. Each bidirectional switch Q is coupled between one of the three-phase input terminals 11 and one of the three-phase output terminals 12. In detail, the bidirectional switch Q RU A bidirectional switch Q is coupled between the first phase input terminal R and the first phase output terminal U; SU The bidirectional switch Q is coupled between the second phase input terminal S and the first phase output terminal U; TU The bidirectional switch Q is coupled between the third phase input terminal T and the first phase output terminal U; RV The bidirectional switch Q is coupled between the first phase input terminal R and the second phase output terminal V; SV The bidirectional switch Q is coupled between the second phase input terminal S and the second phase output terminal V; TV The bidirectional switch Q is coupled between the third phase input terminal T and the second phase output terminal V; RW The bidirectional switch Q is coupled between the first phase input terminal R and the third phase output terminal W; SW The bidirectional switch Q is coupled between the second phase input terminal S and the third phase output terminal W; TW The third phase input terminal T is coupled to the third phase output terminal W.

[0070] like Figure 2As shown, every three bidirectional switches Q form a switch group G. The matrix switch unit 13 includes three switch groups G. The first ends of the bidirectional switches Q of each switch group G are respectively coupled to the three-phase input terminal 11 one-to-one, and the second ends of the bidirectional switches Q of each switch group G are commonly coupled to one of the three-phase output terminals 12, so that these switch groups G are respectively coupled to the three-phase output terminals 12 one-to-one. Before switching the phase power path, only one bidirectional switch Q in each switch group G is bidirectionally turned on (that is, the bidirectional switch Q RU , Q SV , Q TW The first phase input terminal R and the first phase output terminal U are connected via the bidirectional switch Q. RU The first phase power is turned on, so that the first phase power is connected through the first phase line (by the first phase input terminal R, the bidirectional switch Q RU The first phase output terminal U is formed) and supplied to the load terminal 30; the second phase input terminal S and the second phase output terminal V are connected via a bidirectional switch Q SV The second phase power is turned on, so that the second phase power is connected through the second phase line (by the second phase input terminal S, the bidirectional switch Q SV The third phase input terminal T and the third phase output terminal W are connected via a bidirectional switch Q TW The third phase power is turned on, so that the third phase power is connected through the third phase line (by the third phase input terminal T, the bidirectional switch Q TW and the third phase output terminal W) are supplied to the load terminal 30.

[0071] like Figure 2 As shown, in some embodiments, the detection unit 14 is coupled to the three-phase output terminal 12 to detect the line voltage between the phase lines. The control unit 15 receives the detection result of the detection unit 14 and determines to switch the phase power path at an appropriate time point.

[0072] like Figure 2 As shown, in some embodiments, the three single-phase power sources 21 included in the power end 20 are coupled in a delta connection (Δ connection), and the three loads 31 included in the load end 30 are coupled in a delta connection (Δ connection).

[0073] Reference Figure 3 , is a schematic diagram of phase voltage and line voltage of a three-phase power supply in some embodiments of the present invention. Figure 3 The waveforms of three phase voltages Vph1, Vph2, and Vph3 of the three-phase power supply are presented above, and the phases thereof are 120° different from each other. Phase voltage Vph1 is the phase voltage of the first phase power supply, phase voltage Vph2 is the phase voltage of the second phase power supply, and phase voltage Vph3 is the phase voltage of the second phase power supply. Figure 3 The three line voltages V of the three-phase power supply are shown below 12 、V 23 、V31 . Line voltage V 12 is the line voltage between the first phase line and the second phase line, that is, the difference between the phase voltage Vph1 and the phase voltage Vph2. 23 is the line voltage between the second phase line and the third phase line, that is, the difference between the phase voltage Vph2 and the phase voltage Vph3. 31 is the line voltage between the third phase line and the first phase line, that is, the difference between the phase voltage Vph3 and the phase voltage Vph1.

[0074] After receiving the switching signal, the control unit 15 does not switch the phase power path immediately, but waits for an appropriate time to switch. Figure 3 At time point p1 and time point p2, the phase voltage Vph1 and the phase voltage Vph2 intersect each other (line voltage V 12 =0, that is, the voltage difference between the two is the smallest. Switching the phase power path at time point p1 or time point p2 can avoid current surges caused by the large voltage difference between the two phase voltages when switching. Therefore, the control unit 15 will choose to perform phase power path switching at time point p1 or time point p2. At time point p1, the line voltage V 23 In the positive half cycle, at time point p2, the line voltage V 23 It is in the polarity half cycle which is the negative half cycle.

[0075] Here, the first embodiment is used to illustrate the time point p1 (line voltage V 23 In the case of performing phase power path switching in the positive half cycle. Figure 3 , Figure 4 And Table 1. Figure 4 1 is a partial schematic diagram of a matrix switch unit 13 according to a first embodiment of the present invention. At time point p1, both the phase voltage Vph1 and the phase voltage Vph2 are in a positive half cycle, and at this time, the current direction flows from the first end of the bidirectional switch Q (the end coupled to the three-phase input end 11, i.e., the power supply side) to its second end (the end coupled to the three-phase output end 12, i.e., the load side). Each bidirectional switch Q includes a first switch 41 and a second switch 42 connected in series. In the first embodiment, the first switch 41 refers to a unidirectional switch located at the first end (power supply side) of the bidirectional switch Q (hereinafter referred to as a "power supply side switch"), and the second switch 42 refers to a unidirectional switch located at the second end (load side) of the bidirectional switch Q (hereinafter referred to as a "load side switch").

[0076] Table 1

[0077] Positive half cycle Current direction Power supply side to load side First conduction direction Load side to power side Second conduction direction Power supply side to load side

[0078] The first switch 41 is responsible for conducting the first conduction direction. The first conduction direction is opposite to the current direction of the polarity half cycle of the phase power supply coupled to the bidirectional switch Q. In the positive half cycle, the first conduction direction is from the load side to the power supply side. The first switch 41 turns off the first conduction direction when in the off state, that is, blocks the current in the first conduction direction from flowing through the bidirectional switch Q. The first switch 41 turns on the first conduction direction when in the on state, that is, allows the current in the first conduction direction to flow through the bidirectional switch Q.

[0079] The second switch 42 is responsible for conducting the second conduction direction. The second conduction direction is the same as the current direction of the polarity half cycle of the phase power source coupled to the bidirectional switch Q. In the positive half cycle, the second conduction direction is from the power source side to the load side. The second switch 42 turns off the second conduction direction when in the off state, that is, blocks the current in the second conduction direction from flowing through the bidirectional switch Q. The second switch 42 turns on the second conduction direction when in the on state, that is, allows the current in the second conduction direction to flow through the bidirectional switch Q.

[0080] like Figure 4 As shown, the bidirectional switch Q is implemented by two power semiconductor switches connected in reverse series to realize the first switch 41 and the second switch 42. In some embodiments, the power semiconductor switch is presented as a metal oxide semiconductor field effect transistor (MOSFET), but the present invention is not limited to this. For example, the power semiconductor switch can also be a gate isolation transistor (IGBT). Specifically, the drain of the first switch 41 is coupled to the drain of the second switch 42, that is, the common drain is coupled. The source of the first switch 41 is coupled to the corresponding phase input terminal, and the source of the second switch 42 is coupled to the corresponding phase output terminal. The gate of the first switch 41 and the gate of the second switch 42 are coupled to the control unit 15 so that the control unit 15 can control the on and off states of the first switch 41 and the second switch 42.

[0081] In order to avoid the drawings being too complicated, the drawings herein do not show the connection relationship between the gate of the first switch 41 and the gate of the second switch 42 coupled to the control unit 15. Figure 2 As shown, the control unit 15 includes a controller 151 and a gate drive circuit 152. The gate drive circuit 152 receives a low-power signal generated by the controller 151, thereby driving the gate of the power semiconductor switch to turn on or off the power semiconductor switch. The controller 151 is a digital controller, that is, it has functions such as digital signal processing, calculation and control, such as but not limited to a microcontroller, a digital signal processor (Digital Signal Processor, DSP), a field programmable gate array (Field-Programmable Gate Array, FPGA) or an application-specific integrated circuit (Application-Specific Integrated Circuit, ASIC).

[0082] Reference Figure 4 When the first switch 41 is in the on state, the transistor of the first switch 41 is turned on, thereby turning on the first conduction direction of the first switch 41. When the first switch 41 is in the off state, the transistor of the first switch 41 is turned off, and the body diode of the first switch 41 blocks the current in the first conduction direction, thereby turning off the first conduction direction of the first switch 41.

[0083] When the second switch 42 is in the on state, the transistor of the second switch 42 is turned on, thereby turning on the second conduction direction of the second switch 42. When the second switch 42 is in the off state, the transistor of the second switch 42 is turned off, and the body diode of the second switch 42 blocks the current in the second conduction direction, thereby turning off the second conduction direction of the second switch 42.

[0084] Reference Figure 5 , is a flow chart of phase power path switching in some embodiments of the present invention. After receiving the switching signal, the control unit 15 (controller 151) executes the following Figure 5 The process shown.

[0085] In step S51, the control unit 15 obtains two line voltages (the first line voltage V XY , the second line voltage V YZ ) value. Here, the first line voltage V XY is the line voltage V 12 , the second line voltage V YZ is the line voltage V 23 .

[0086] Step S52 is the first line voltage V XY Zero-crossing detection. That is, the control unit 15 determines the first line voltage V XY Is it zero? If yes, proceed to step S53; if no, continue to wait for the first line voltage V in step S52. XY It is zero point.

[0087] Step S53 is the second line voltage V YZ Polarity half-cycle detection. That is, the control unit 15 determines the second line voltage V YZ In the first embodiment, the control unit 15 determines the second line voltage V YZ In the positive half cycle.

[0088] After step S52 and step S53, the time point p1 is found. That is, the control unit 15 detects the first line voltage V XY is zero and the second line voltage V YZ In the half cycle of the positive half cycle. Figures 5 to 10The phase power path switching process of the first embodiment is described. Figure 6 FIG. 4 is a timing diagram of the phase power path switching process according to the first embodiment of the present invention. Figures 7 to 10 Schematic diagrams (I) to (IV) of some circuit states of the matrix switch unit 13 according to the first embodiment of the present invention. Figure 6 At time t1, the line voltage V 12 is the zero point, the line voltage V 23 In the positive half cycle), the control unit 15 then executes steps S54 to S57.

[0089] Step S54 is to perform short circuit protection of the X-th phase line and the Y-th phase line. Specifically, the control unit 15 turns off the first conduction direction of the bidirectional switch Q of the X-th phase line and the Y-th phase line. Figure 6 and Figure 7 Here, the Xth phase line is the first phase line, and the Yth phase line is the second phase line. At time t1, the control unit 15 turns on the bidirectional switch Q RU , Q SV The first conduction direction of the bidirectional switch Q is turned off. RU , Q SV The first switch 41 in the circuit is closed. RU , Q SV The first switch 41 in the circuit is closed because the first and second phase power supplies are in the positive half cycle, and the bidirectional switch Q RU , Q SV The body diode in the Q is still turned on due to the forward bias, so the first and second phase power are still transmitted to the load end 30 through the first and second phase lines. RU , Q SV The reverse cutoff characteristic of the body diode of the first switch 41 ensures that when the alternative path is turned on in the subsequent step, reverse current will not flow through the first and second phase lines to cause a short circuit at the power supply terminal 20.

[0090] Step S55 is to conduct the first and second alternative paths in the forward direction. Specifically, the control unit 15 turns on the second conduction direction of the bidirectional switch Q of the alternative paths of the X-th and Y-th phase lines. The alternative path of the X-th phase line is from the X-th phase input terminal to the Y-th phase output terminal; the alternative path of the Y-th phase line is from the Y-th phase input terminal to the X-phase output terminal. Figure 6 and Figure 8 Here, the Xth phase line is the first phase line, and the Yth phase line is the second phase line. The first alternative path is from the first phase input terminal R to the second phase output terminal V; the second alternative path is from the second phase input terminal S to the first phase output terminal U. At time t2, the control unit 15 turns on the bidirectional switch Q RV , Q SU The second conduction direction of the bidirectional switch Q is turned on. RV , QSU The second switch 42 in is turned on. At time t2, the voltage V UV is positive, that is, the voltage at the first phase input terminal R is greater than the voltage at the second phase input terminal S. RV , Q SU After the second switch 42 in the circuit is turned on, since the voltage at the first phase input terminal R is greater than the voltage at the second phase input terminal S, the second phase output terminal V is changed to receive the power supply from the first phase input terminal R, so the voltage V UV is zero, the voltage V UV Enter the power hold time. And, if Figure 2 As shown, the load terminal 30 is Δ-connected. According to Kirchhoff's Voltage Law (KVL), the voltage V UV The falling part is caused by the voltage V VW Complement, voltage V VW By voltage V ST Increase to voltage V ST +V RS .

[0091] Step S56 is to disconnect the Xth and Yth phase lines. Specifically, the control unit 15 turns off the second conduction direction of the bidirectional switch Q of the Xth and Yth phase lines. Figure 6 and Fig. 9 Here, the Xth phase line is the first phase line, and the Yth phase line is the second phase line. At time t3, the control unit 15 turns on the bidirectional switch Q RU , Q SV The second conduction direction of the bidirectional switch Q is turned off. RU , Q SV The second switch 42 in the circuit is turned off. In this way, the bidirectional switch Q RU , Q SV The first switch 41 and the second switch 42 are both closed, so that the bidirectional switch Q RU , Q SV Therefore, the phase power is not transmitted to the load terminal 30 via the first phase line and the second phase line. The first phase power of the first phase input terminal R is disconnected from the first phase output terminal U, and the first phase output terminal U receives the second phase power of the second phase input terminal S instead. Therefore, the voltage V UV -V RS , voltage V UV Leave the power supply to maintain time. And, refer to Figure 2 and Fig. 9 According to Kirchhoff's voltage law, the voltage V UV The falling part is caused by the voltage V WU Complement, voltage V WU By voltage V TR Increase to voltage V TR+V RS .

[0092] Step S57 is to negatively conduct the first and second alternative paths. Specifically, the control unit 15 turns on the first conduction direction of the bidirectional switch Q of the alternative paths of the X-th and Y-th phase lines. The alternative path of the X-th phase line is from the X-th phase input terminal to the Y-th phase output terminal; the alternative path of the Y-th phase line is from the Y-th phase input terminal to the X-phase output terminal. Figure 6 and Fig.10 Here, the X-th phase line is the first phase line, and the Y-th phase line is the second phase line. The first alternative path is from the first phase input terminal R to the second phase output terminal V; the second alternative path is from the second phase input terminal S to the first phase output terminal U. At time t4, the control unit 15 turns on the bidirectional switch Q RV , Q SU The first conduction direction of the bidirectional switch Q is turned on to cancel the short-circuit protection of the two alternative paths. RV , Q SU The first switch 41 in the circuit is turned on. In this way, the bidirectional switch Q RV , Q SU The first switch 41 and the second switch 42 are both turned on, so that the bidirectional switch Q RV , Q SU Thus, the first phase power and the second phase power are supplied to the load end 30 via the first and second alternative paths respectively, completing the phase power path switching.

[0093] For ease of understanding, in the first embodiment, the switch actions in the aforementioned steps S54 to S57 are summarized as shown in Table 2. Through the aforementioned steps S54 to S57, the power terminal 20 can be prevented from short-circuiting during the path switching process, and the current can be kept flowing during the path switching process, thereby increasing the power supply maintenance time capability and preventing the load terminal 30 from being open-circuited. In addition, the use of a bidirectional switch can have effects such as fast switching and zero current switching (ZCS). After the phase power path switching is finally completed, load balance (or power balance) can be achieved.

[0094] Table 2

[0095]

[0096] Next, the second embodiment of the present invention is described. The phase power path switching circuit 10 of the second embodiment is as described in the first embodiment (refer to Figure 2 The difference from the first embodiment is that the second embodiment is at time point p2 (line voltage V 23 In the negative half cycle), the phase power path switching is performed. That is, after step S52 and step S53, the control unit 15 of the second embodiment detects the first line voltage VXY is zero and the second line voltage V YZ In the negative half cycle, steps S54 to S57 are executed. Figure 3 , Fig.11 And Table 3. Fig.11 It is a partial schematic diagram of the matrix switch unit of the second embodiment of the present invention. At time point p2, the phase voltage Vph1 and the phase voltage Vph2 are both in the negative half cycle, and the current direction at this time is from the second end of the bidirectional switch Q (the end coupled to the three-phase output end 12, i.e., the load side) to its first end (the end coupled to the three-phase input end 11, i.e., the power supply side). Similar to the first embodiment, in the second embodiment, the first switch 41 is also responsible for the conduction of the first conduction direction (the current direction of the half cycle opposite to the polarity of the phase power supply coupled to this bidirectional switch Q), and the second switch 42 is also responsible for the conduction of the second conduction direction (the current direction of the half cycle of the polarity of the phase power supply coupled to this bidirectional switch Q). In the negative half cycle, the first conduction direction is from the power supply side to the load side, and the second conduction direction is from the load side to the power supply side. Since the first and second conduction directions of the second embodiment are opposite to those of the first embodiment, in the second embodiment, the first switch 41 refers to a unidirectional switch located at the second end (load side) of the bidirectional switch Q, and the second switch 42 refers to a unidirectional switch located at the first end (power side) of the bidirectional switch Q. That is, the source of the first switch 41 is coupled to the corresponding phase output end, and the source of the second switch 42 is coupled to the corresponding phase input end. In the second embodiment, the bidirectional switch Q RU , Q SU , Q RV , Q SV The operation timing of the first switch 41 and the second switch 42 is the same as that of the above Figure 6 The switch actions are summarized in Table 4 and will not be repeated here.

[0097] Table 3

[0098] Negative half cycle Current direction Load side to power side First conduction direction Power supply side to load side Second conduction direction Load side to power side

[0099] Table 4

[0100]

[0101]

[0102] Next, the third embodiment of the present invention is described. At time point p1 (line voltage V 23 In the case of performing phase power path switching in the positive half cycle. Fig.12 and Fig.13 . Fig.12 1 is a circuit diagram of a phase power path switching circuit 10 according to the third and fourth embodiments of the present invention. Fig.13It is a partial schematic diagram of a matrix switch unit according to the third embodiment of the present invention. The phase power path switching circuit 10 of the third embodiment is substantially the same as the phase power path switching circuit 10 of the first embodiment, except that the first switch 41 and the second switch 42 in the bidirectional switch Q of the third embodiment are coupled to a common source, that is, the source of the first switch 41 is coupled to the source of the second switch 42. In the third embodiment, the first switch 41 refers to a unidirectional switch located at the second end (load side) of the bidirectional switch Q, and the second switch 42 refers to a unidirectional switch located at the first end (power side) of the bidirectional switch Q. That is, the drain of the first switch 41 is coupled to the corresponding phase output end, and the drain of the second switch 42 is coupled to the corresponding phase input end. Compared with the first embodiment, the first switch 41 and the second switch 42 of the third embodiment are only different in position, and their functions are still the same as those of the first switch 41 and the second switch 42 of the first embodiment. Therefore, the bidirectional switch Q RU , Q SU , Q RV , Q SV The operation timing of the first switch 41 and the second switch 42 is the same as that of the above Figure 6 The switch action is the same as Table 4 and will not be repeated here.

[0103] Next, the fourth embodiment of the present invention is described. At time point p2 (line voltage V 23 In the case of performing phase power path switching in the negative half cycle. Fig.12 and Fig.14 , Fig.14 This is a partial schematic diagram of a matrix switch unit according to a fourth embodiment of the present invention. In the fourth embodiment, the first switch 41 refers to a unidirectional switch located at the first end (power supply side) of the bidirectional switch Q, and the second switch 42 refers to a unidirectional switch located at the second end (load side) of the bidirectional switch Q. That is, the drain of the first switch 41 is coupled to the corresponding phase input end, and the drain of the second switch 42 is coupled to the corresponding phase output end. Compared with the second embodiment, the first switch 41 and the second switch 42 of the fourth embodiment are only different in position, and their functions are still the same as the first switch 41 and the second switch 42 of the second embodiment. Therefore, the bidirectional switch Q RU , Q SU , Q RV , Q SV The operation timing of the first switch 41 and the second switch 42 is the same as that of the above Figure 6 The switch action is the same as Table 2 and will not be repeated here.

[0104] Reference Fig.15, is a circuit diagram of a phase power path switching circuit 10 according to a fifth embodiment of the present invention. Compared with the first embodiment, the fifth embodiment is mainly an example. In some embodiments, the detection unit 14 is coupled to the three-phase input terminal 11 to detect the line voltage between the phase lines. Figure 6 Before time t1), the bidirectional switch Q RU , Q SV , Q TW Bidirectional opening, that is, each phase input terminal is connected to the corresponding phase output terminal. Therefore, the detection unit 14 coupled to the three-phase input terminal 11 and coupled to the three-phase output terminal 12 can achieve the same effect. Therefore, the fifth to eighth embodiments of the present invention are similar to the first to fourth embodiments described above, respectively, and the difference is that the detection unit 14 of the fifth to eighth embodiments is coupled to the three-phase input terminal 11. In this way, the aforementioned steps S51 to S57 can also be executed to complete the phase power path switching.

[0105] Reference Fig.16 , is a circuit diagram of a phase power path switching circuit 10 of a ninth embodiment of the present invention. The ninth embodiment is mainly an example. In some embodiments, the three single-phase power sources 21 included in the power terminal 20 are coupled in a star connection (Y connection), and the three loads 31 included in the load terminal 30 are coupled in a star connection (Y connection). Since the present invention detects the line voltage V 12 ,V 23 ,V 31 Therefore, the coupling method of the power supply terminal 20 and the load terminal 30 does not affect the execution of the aforementioned steps S51 to S57. Therefore, the phase power path switching circuits 10 of the ninth to sixteenth embodiments of the present invention are respectively the same as the phase power path switching circuits 10 of the first to eighth embodiments, and the only difference is that the power supply terminal 20 and the load terminal 30 are coupled in a star connection (Y connection).

[0106] Reference Fig.17 , is a circuit diagram of a phase power path switching circuit 10 according to the seventeenth embodiment of the present invention. The seventeenth embodiment is mainly an example. In some embodiments, the three single-phase power sources 21 included in the power terminal 20 are coupled in a star connection (Y connection), and the three loads 31 included in the load terminal 30 are coupled in a delta connection (Δ connection). Since the present invention detects the line voltage V 12 ,V 23 ,V 31 Therefore, the coupling method of the power supply terminal 20 and the load terminal 30 does not affect the execution of the aforementioned steps S51 to S57. Therefore, the phase power supply path switching circuit 10 of the eighteenth to twenty-fourth embodiments of the present invention is respectively the same as the phase power supply path switching circuit 10 of the aforementioned first to eighth embodiments, and the only difference is that the power supply terminal 20 is coupled in a star connection (Y connection). To facilitate understanding of the differences between the various embodiments of the present invention, they are summarized as shown in Table 5.

[0107] Table 5

[0108]

[0109]

[0110] Although the above embodiments are described with the bidirectional switches Q being all coupled to a common drain or all coupled to a common source, in other embodiments, some of the bidirectional switches Q may be implemented with a common drain coupling structure, and another part of the bidirectional switches Q may be implemented with a common source coupling structure, and the switch control may be adjusted accordingly, and the above steps S54 to S57 may still be implemented. Due to the numerous combinations, they are not listed one by one.

[0111] Although the above embodiment describes the determination of two time points (p1 and p2), it does not limit the control unit 15 of the present invention to be able to detect both time points (p1 and p2). The control unit 15 only needs to detect one of the two time points (p1 and p2).

[0112] Although the above embodiment describes that the matrix switch unit 13 has nine bidirectional switches Q, the present invention is not limited to this number. For example, if it is preset that only a certain two-phase line (X, Y) needs to be switched, the bidirectional switch Q coupled to another phase line (Z) can be omitted. For example, in the above embodiment, the bidirectional switch Q associated with the third phase line (coupled to the third phase input terminal T or / and the third phase output terminal W) is switched between the first phase line and the second phase line. TU , Q TV , Q RW , Q SW It can be omitted.

[0113] According to some embodiments of the present invention, the phase power path switching circuit 10 only needs to use voltage detection without current detection, and does not need to consider the phase sequence of the three-phase power supply. The switching time point can be determined by detecting the two-line voltage, and is applicable to a variety of connection architectures between the power supply end 20 and the load end 30, with plug-and-play convenience and versatility. After switching the phase power path, the loads coupled to the two-phase lines are exchanged with each other, so that the load balancing effect can be achieved. In addition, through the switch switching sequence of the aforementioned steps S54 to S57, the short circuit of the power supply end 20 and the open circuit of the load end 30 can be avoided during the path switching process. And the use of a bidirectional switch can have the effects of fast switching and zero current switching (flexible switching).

[0114] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A phase power path switching circuit, receiving a three-phase power supply from a power supply end, characterized in that: The phase power path switching circuit includes: A three-phase input terminal, including a first phase input terminal, a second phase input terminal and a third phase input terminal, respectively receiving the three-phase power supply of the power supply terminal; The three-phase output terminal includes a first phase output terminal, a second phase output terminal and a third phase output terminal; A matrix switch unit, comprising a plurality of bidirectional switches, each of the bidirectional switches being coupled between one of the three-phase input terminals and one of the three-phase output terminals, wherein the first-phase input terminal and the first-phase output terminal are coupled via a first bidirectional switch among the bidirectional switches to form a first phase line, and the second-phase input terminal and the second-phase output terminal are coupled via a second bidirectional switch among the bidirectional switches to form a second phase line; a detection unit configured to detect the first phase line, the second phase line and a third phase line, the third phase line being coupled between the third phase input terminal and the third phase output terminal; and A control unit is coupled to the detection unit and the matrix switch unit, and is configured to, after receiving a switching signal, execute the following operations in sequence in response to detecting that a first line voltage between the first phase line and the second phase line is zero and a second line voltage between the second phase line and the third phase line is within a polarity half cycle: (a) turning off a first conduction direction of the first bidirectional switch and the second bidirectional switch, wherein the first conduction direction is opposite to a current direction of the polarity half cycle; (b) turning on a second conduction direction of a third bidirectional switch and a fourth bidirectional switch among the bidirectional switches, the second conduction direction being the same as the current direction of the polarity half cycle, wherein the third bidirectional switch is coupled between the second phase input terminal and the first phase output terminal, and the fourth bidirectional switch is coupled between the first phase input terminal and the second phase output terminal; (c) turning off the second conduction direction of the first bidirectional switch and the second bidirectional switch; and (d) Turning on the first conduction direction of the third bidirectional switch and the fourth bidirectional switch.

2. The phase power path switching circuit according to claim 1, characterized in that: The polarity half cycle is selected from one of a group consisting of a positive half cycle and a negative half cycle.

3. The phase power path switching circuit according to claim 1, wherein: Each of the bidirectional switches includes a first switch and a second switch connected in series. The first switch turns off the first conduction direction when in an off state, and the second switch turns off the second conduction direction when in an off state.

4. The phase power path switching circuit according to claim 3, characterized in that: The first switch turns on the first conduction direction when in an on state, and the second switch turns on the second conduction direction when in an on state.

5. The phase power path switching circuit according to claim 3 or 4, characterized in that: The first switch and the second switch are two power semiconductor switches connected in reverse series.

6. The phase power path switching circuit according to claim 5, characterized in that: The power semiconductor switch is a metal oxide semiconductor field effect transistor, the first switch and the second switch respectively have a source, a gate and a drain, the drain of the first switch is coupled to the drain of the second switch, the source of the first switch and the source of the second switch are respectively coupled to the corresponding phase input terminal and the phase output terminal, and the gate of the first switch and the gate of the second switch are coupled to the control unit.

7. The phase power path switching circuit according to claim 6, characterized in that: The polarity half cycle is a positive half cycle, the source of the first switch is coupled to the corresponding phase input terminal, and the source of the second switch is coupled to the corresponding phase output terminal.

8. The phase power path switching circuit according to claim 6, wherein: The polarity half cycle is a negative half cycle, the source of the first switch is coupled to the corresponding phase output terminal, and the source of the second switch is coupled to the corresponding phase input terminal.

9. The phase power path switching circuit according to claim 5, characterized in that: The power semiconductor switch is a metal oxide semiconductor field effect transistor, the first switch and the second switch respectively have a source, a gate and a drain, the source of the first switch is coupled to the source of the second switch, the drain of the first switch and the drain of the second switch are respectively coupled to the corresponding phase input terminal and the phase output terminal, and the gate of the first switch and the gate of the second switch are coupled to the control unit.

10. The phase power path switching circuit according to claim 9, characterized in that: The polarity half cycle is a positive half cycle, the drain of the first switch is coupled to the corresponding phase output terminal, and the drain of the second switch is coupled to the corresponding phase input terminal.

11. The phase power path switching circuit according to claim 9, wherein: The polarity half cycle is a negative half cycle, the drain of the first switch is coupled to the corresponding phase input terminal, and the drain of the second switch is coupled to the corresponding phase output terminal.

12. The phase power path switching circuit according to claim 1, wherein: The detection unit is coupled to the three-phase input terminal.

13. The phase power path switching circuit according to claim 1, wherein: The detection unit is coupled to the three-phase output terminal.

14. The phase power path switching circuit according to claim 1, wherein: Every three of the bidirectional switches form a switch group. The matrix switch unit includes three switch groups, and is characterized in that the two ends of each of the bidirectional switches are respectively a first end and a second end, the first ends of the bidirectional switches of each of the switch groups are respectively coupled to the three-phase input end in a one-to-one manner, and the second ends of the bidirectional switches of each of the switch groups are commonly coupled to one of the three-phase output ends, so that the switch groups are respectively coupled to the three-phase output ends in a one-to-one manner, wherein the third phase line is formed by coupling the third phase input end and the third phase output end via a fifth bidirectional switch among the bidirectional switches.

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