Power unit
阅读说明：本技术 功率单元 (Power unit ) 是由 应建平 刘腾 娄德海 王欣 曹赟 于 2019-03-27 设计创作，主要内容包括：本发明提供一种功率单元,包括：DC/DC变换电路；旁路电路,包括：机械开关单元,阻抗网络,以及半导体开关单元,其中,半导体开关单元和阻抗网络串联连接形成串联支路,串联支路、机械开关单元以及DC/DC变换电路并联连接于功率单元的一侧的正端和负端之间；检测单元,用以检测并根据DC/DC变换电路的工作信号产生检测信号；以及控制单元,用以接收并根据检测信号来判断DC/DC变换电路是否发生故障,当DC/DC变换电路发生故障时,控制单元输出第一闭合控制信号至机械开关单元的控制端以及输出第二闭合控制信号至半导体开关单元的控制端,使得半导体开关单元先于机械开关单元闭合。(The present invention provides a power unit, comprising: a DC/DC conversion circuit; a bypass circuit, comprising: the power unit comprises a mechanical switch unit, an impedance network and a semiconductor switch unit, wherein the semiconductor switch unit and the impedance network are connected in series to form a series branch, and the series branch, the mechanical switch unit and the DC/DC conversion circuit are connected in parallel between a positive end and a negative end of one side of the power unit; a detection unit for detecting and generating a detection signal according to the working signal of the DC/DC conversion circuit; and the control unit is used for receiving and judging whether the DC/DC conversion circuit has a fault according to the detection signal, and when the DC/DC conversion circuit has the fault, the control unit outputs a first closing control signal to the control end of the mechanical switch unit and outputs a second closing control signal to the control end of the semiconductor switch unit so that the semiconductor switch unit is closed before the mechanical switch unit.)
1. A power cell, comprising:
a DC/DC conversion circuit;
a bypass circuit, comprising: the DC/DC conversion circuit comprises a mechanical switch unit, an impedance network and a semiconductor switch unit, wherein the semiconductor switch unit and the impedance network are connected in series to form a series branch, a first end of the mechanical switch unit and a positive end of one side of the DC/DC conversion circuit are electrically connected with a positive end of one side of the power unit, and a second end of the mechanical switch unit, a second end of the series branch and a negative end of one side of the DC/DC conversion circuit are electrically connected with a negative end of one side of the power unit;
the detection unit is used for detecting a working signal of the DC/DC conversion circuit and generating a detection signal according to the working signal; and
and the control unit is used for receiving and judging whether the DC/DC conversion circuit has a fault according to the detection signal, and when the DC/DC conversion circuit has the fault, the control unit outputs a first closing control signal to the control end of the mechanical switch unit and outputs a second closing control signal to the control end of the semiconductor switch unit so that the semiconductor switch unit is closed before the mechanical switch unit.
2. The power unit of claim 1, further comprising an auxiliary power source for providing power to the detection unit and the control unit.
3. The power unit of claim 1, the DC/DC conversion circuit comprising a DC bus capacitor, wherein a positive terminal of the DC bus capacitor is electrically connected to a positive terminal of the one side of the DC/DC conversion circuit and a negative terminal of the DC bus capacitor is electrically connected to a negative terminal of the one side of the DC/DC conversion circuit.
4. The power cell of claim 3, the bypass circuit further comprising a diode, wherein an anode of the diode is connected to the first end of the series branch and a cathode of the diode is connected to a positive terminal of the DC bus capacitance.
5. The power cell of claim 3, the bypass circuit further comprising a diode, wherein an anode of the diode is connected to a negative terminal of the DC bus capacitor and a cathode of the diode is connected to the second terminal of the series branch.
6. The power unit of any of claims 1-5, wherein the control unit outputs the first close control signal and the second close control signal simultaneously.
7. The power unit according to any of claims 1-5, wherein the control unit outputs the second close control signal first, delays for a first predetermined time, and outputs the first close control signal; or the control unit outputs the first closing control signal first, delays a second preset time and then outputs the second closing control signal, wherein the closing time required by the mechanical switch is longer than the second preset time.
8. The power unit according to any of claims 1-5, wherein the control unit is further configured to output a shutdown control signal for controlling the DC/DC conversion circuit to stop operating when the DC/DC conversion circuit fails.
9. The power unit according to any of claims 1-5, wherein the mechanical switch unit is constituted by a single mechanical switch, or by a plurality of mechanical switches connected in series or in parallel.
10. The power unit of any of claims 1-5, wherein the impedance network is a resistor, an inductor, or a capacitor, or a series-parallel configuration of a resistor, a capacitor, and an inductor.
11. A power unit according to any of claims 1-5, characterized in that the semiconductor switch unit is formed by a single semiconductor switch or by a plurality of semiconductor switches connected in series or in parallel.
12. A power unit comprising
A plurality of power converters having one side connected in series to form one side of the power cell, each of the power converters including a DC/DC conversion circuit and a bypass circuit, each of the bypass circuits including a mechanical switching element, an impedance network, and a semiconductor switching element, wherein the semiconductor switch unit and the impedance network are connected in series to form a series branch, a first end of the mechanical switch unit, a positive terminal of one side of the DC/DC conversion circuit are electrically connected with a corresponding positive terminal of the one side of the power converter, a second end of the mechanical switch unit, a second end of the series branch, and a negative end of the one side of the DC/DC conversion circuit are electrically connected to a negative end of the corresponding one side of the power converter;
the detection unit is used for detecting working signals of the plurality of DC/DC conversion circuits and generating corresponding detection signals according to the working signals; and
and the control unit is used for receiving and judging whether one or more of the DC/DC conversion circuits of the power converter has a fault according to the detection signal, and when one or more of the DC/DC conversion circuits has a fault, the control unit outputs a corresponding first closing control signal to the control end of the mechanical switch unit of the corresponding power converter and outputs a corresponding second closing control signal to the control end of the semiconductor switch unit of the corresponding power converter, so that the semiconductor switch unit is closed before the mechanical switch unit.
13. The power unit of claim 12, further comprising an auxiliary power source for supplying power to the detection unit and the control unit.
14. The power unit of claim 12, the DC/DC conversion circuit comprising a DC bus capacitor, wherein a positive terminal of the DC bus capacitor is electrically connected to a positive terminal of the one side of the DC/DC conversion circuit and a negative terminal of the DC bus capacitor is electrically connected to a negative terminal of the one side of the DC/DC conversion circuit.
15. The power cell of claim 14, the bypass circuit further comprising a diode, wherein an anode of the diode is connected to the first end of the series branch and a cathode of the diode is connected to a positive terminal of the dc bus capacitance.
16. The power cell of claim 14, the bypass circuit further comprising a diode, wherein an anode of the diode is connected to a negative terminal of the dc bus capacitor and a cathode of the diode is connected to the second terminal of the series branch.
17. The power unit according to any of claims 12-16, wherein the control unit outputs the first close control signal and the second close control signal simultaneously.
18. The power unit according to any of claims 12-16, wherein the control unit outputs the second close control signal first, delays for a first predetermined time, and outputs the first close control signal; or the control unit outputs the first closing control signal first, delays a second preset time and then outputs the second closing control signal, wherein the closing time required by the mechanical switch is longer than the second preset time.
19. The power unit according to any of claims 12-16, wherein when one or more of the DC/DC conversion circuits fails, the control unit further outputs a corresponding shutdown control signal to cause the failed DC/DC conversion circuit to stop operating.
20. The power unit according to any of claims 12-16, wherein the mechanical switching unit is constituted by a single mechanical switch, or by a plurality of mechanical switches connected in series or in parallel.
21. The power unit according to any of claims 12-16, wherein the impedance network is a resistor, an inductor, or a capacitor, or a series-parallel configuration of a resistor, a capacitor, and an inductor.
22. A power unit according to any of claims 12-16, wherein the semiconductor switch unit is formed by a single semiconductor switch or by a plurality of semiconductor switches connected in series or in parallel.
Technical Field
The invention relates to the technical field of power electronic conversion, in particular to a power unit.
Background
In a high-voltage DC-DC conversion situation, a power electronic conversion system formed by connecting a plurality of DC/DC modules in series is often used to realize a high-voltage DC-DC conversion function, as shown in fig. 1, when a certain DC/DC module in the system fails, the normal operation of the whole system will be directly affected, and therefore the failed DC/DC module needs to be bypassed in time to ensure that the system is not affected by the failed DC/DC module and can continue to operate stably.
However, the prior art technique of bypassing a faulty DC/DC module has several problems:
1. due to the bus voltage V of the power electronic conversion systemDC1The voltage of the serial side of each DC/DC module is invariable, and the bypass fault DC/DC module inevitably causes the change of the voltage of the serial side of each DC/DC module, however, each DC/DC module has a direct current bus capacitor, and the bypass fault DC/DC module inevitably generates larger current impact in a serial branch circuit, which may cause overcurrent damage of related devices;
after the DC/DC module fails, the DC/DC module needs to be quickly bypassed, otherwise, the failure of a single DC/DC module can affect the stability of the whole system;
3. when we use semiconductor devices to achieve fast action of the bypass, new problems are brought about. Under normal conditions, after the fault DC/DC module is bypassed, the system can continue to operate, if the system is restarted after power failure, the semiconductor device cannot work due to the power failure of the control circuit, and the fault DC/DC module cannot be bypassed in advance during restarting, so that the reliability of the system is affected.
Therefore, a new bypass circuit needs to be designed.
The above information disclosed in this background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not constitute prior art that is already known to a person of ordinary skill in the art.
Disclosure of Invention
The present invention is directed to a power cell that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
Additional features and advantages of the invention will be set forth in the detailed description which follows, or may be learned by practice of the invention.
According to a first aspect of the invention, a power unit is disclosed, comprising:
a DC/DC conversion circuit;
a bypass circuit, comprising: the DC/DC conversion circuit comprises a mechanical switch unit, an impedance network and a semiconductor switch unit, wherein the semiconductor switch unit and the impedance network are connected in series to form a series branch, a first end of the mechanical switch unit and a positive end of one side of the DC/DC conversion circuit are electrically connected with a positive end of one side of the power unit, and a second end of the mechanical switch unit, a second end of the series branch and a negative end of the one side of the DC/DC conversion circuit are electrically connected with a negative end of the one side of the power unit;
the detection unit is used for detecting a working signal of the DC/DC conversion circuit and generating a detection signal according to the working signal; and
and the control unit is used for receiving and judging whether the DC/DC conversion circuit has a fault according to the detection signal, and when the DC/DC conversion circuit has the fault, the control unit outputs a first closing control signal to the control end of the mechanical switch unit and outputs a second closing control signal to the control end of the semiconductor switch unit so that the semiconductor switch unit is closed before the mechanical switch unit.
According to an exemplary embodiment of the invention, the power unit further comprises an auxiliary power supply for supplying electrical energy to the detection unit and the control unit.
According to an exemplary embodiment of the invention, the DC/DC converter circuit comprises a DC bus capacitor, wherein a positive terminal of the DC bus capacitor is electrically connected to a positive terminal of the one side of the DC/DC converter circuit and a negative terminal of the DC bus capacitor is electrically connected to a negative terminal of the one side of the DC/DC converter circuit.
According to an example embodiment of the present invention, the bypass circuit further comprises a diode, wherein an anode of the diode is connected to the first end of the series branch and a cathode of the diode is connected to a positive terminal of the dc bus capacitor.
According to an exemplary embodiment of the invention, the bypass circuit further comprises a diode, wherein an anode of the diode is connected to a negative terminal of the dc bus capacitor and a cathode of the diode is connected to the second terminal of the series branch.
According to an example embodiment of the present invention, the control unit outputs the first closing control signal and the second closing control signal at the same time.
According to an example embodiment of the present invention, the control unit outputs the second close control signal first, delays for a first predetermined time, and then outputs the first close control signal; or the control unit outputs the first closing control signal first, delays a second preset time and then outputs the second closing control signal, wherein the closing time required by the mechanical switch is longer than the second preset time.
According to an exemplary embodiment of the present invention, when the DC/DC conversion circuit fails, the control unit is further configured to output a shutdown control signal for controlling the DC/DC conversion circuit to stop operating.
According to an exemplary embodiment of the present invention, wherein the mechanical switch unit is constituted by a single mechanical switch, or by a plurality of mechanical switches connected in series or in parallel.
According to an example embodiment of the present invention, the impedance network is a resistor, an inductor or a capacitor, or a series-parallel structure of a resistor, a capacitor and an inductor.
According to an exemplary embodiment of the present invention, wherein the semiconductor switch unit is constituted by a single semiconductor switch, or by a plurality of semiconductor switches connected in series or in parallel.
According to a second aspect of the invention, a power cell is disclosed, comprising
A plurality of power converters having one side connected in series to form one side of the power cell, each of the power converters including a DC/DC conversion circuit and a bypass circuit, each of the bypass circuits including a mechanical switching element, an impedance network, and a semiconductor switching element, wherein the semiconductor switch unit and the impedance network are connected in series to form a series branch, a first end of the mechanical switch unit, a positive terminal of one side of the DC/DC conversion circuit are electrically connected with a corresponding positive terminal of the one side of the power converter, a second end of the mechanical switch unit, a second end of the series branch, and a negative end of the one side of the DC/DC conversion circuit are electrically connected to a negative end of the corresponding one side of the power converter;
the detection unit is used for detecting working signals of the plurality of DC/DC conversion circuits and generating corresponding detection signals according to the working signals; and
and the control unit is used for receiving and judging whether one or more of the DC/DC conversion circuits of the power converter has a fault according to the detection signal, and when one or more of the DC/DC conversion circuits has a fault, the control unit outputs a corresponding first closing control signal to the control end of the mechanical switch unit of the corresponding power converter and outputs a corresponding second closing control signal to the control end of the semiconductor switch unit of the corresponding power converter, so that the semiconductor switch unit is closed before the mechanical switch unit.
According to an example embodiment of the present invention, the power unit further comprises an auxiliary power source for supplying power to the detection unit and the control unit.
According to an exemplary embodiment of the invention, the DC/DC converter circuit comprises a DC bus capacitor, wherein a positive terminal of the DC bus capacitor is electrically connected to a positive terminal of the one side of the DC/DC converter circuit and a negative terminal of the DC bus capacitor is electrically connected to a negative terminal of the one side of the DC/DC converter circuit.
According to an example embodiment of the present invention, the bypass circuit further comprises a diode, wherein an anode of the diode is connected to the first end of the series branch and a cathode of the diode is connected to a positive terminal of the dc bus capacitor.
According to an exemplary embodiment of the invention, the bypass circuit further comprises a diode, wherein an anode of the diode is connected to a negative terminal of the dc bus capacitor and a cathode of the diode is connected to the second terminal of the series branch.
According to an example embodiment of the present invention, the control unit outputs the first closing control signal and the second closing control signal at the same time.
According to an example embodiment of the present invention, the control unit outputs the second close control signal first, delays for a first predetermined time, and then outputs the first close control signal; or the control unit outputs the first closing control signal first, delays a second preset time and then outputs the second closing control signal, wherein the closing time required by the mechanical switch is longer than the second preset time.
According to an example embodiment of the present invention, when one or more of the DC/DC conversion circuits malfunctions, the control unit further outputs a corresponding shutdown control signal so that the malfunctioning DC/DC conversion circuit stops operating.
According to an exemplary embodiment of the present invention, wherein the mechanical switch unit is constituted by a single mechanical switch, or by a plurality of mechanical switches connected in series or in parallel.
According to an example embodiment of the present invention, the impedance network is a resistor, an inductor or a capacitor, or a series-parallel structure of a resistor, a capacitor and an inductor.
According to an exemplary embodiment of the present invention, wherein the semiconductor switch unit is constituted by a single semiconductor switch, or by a plurality of semiconductor switches connected in series or in parallel.
According to some embodiments of the invention, the bypass circuit topology of the power unit effectively suppresses current surge generated in bypassing through the impedance network; in addition, the topology of the bypass circuit is applied to the DC/DC conversion occasion, and the effect that the bypass of the fault power unit can be maintained even if the auxiliary power supply is power-off is realized while the rapidity of the bypass action is realized by using the semiconductor switch; the current is switched to the mechanical switch branch circuit after bypassing, and the loss of a bypass circuit is small.
According to some embodiments of the present invention, further, the present invention enables a smaller current surge to be generated in the DC/DC conversion circuit during the bypass process by adding a diode.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
Drawings
The above and other objects, features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings.
FIG. 1 shows a schematic diagram of a DC/DC conversion system having a series configuration;
FIG. 2 shows a schematic diagram of a power cell according to an example embodiment of the invention;
FIG. 3 shows a schematic diagram of a DC/DC conversion system incorporating a power cell of an exemplary embodiment of the present invention;
FIG. 4 shows a schematic diagram of a power cell with a diode according to an example embodiment of the invention;
FIG. 5 shows a schematic diagram of another power cell with a diode according to an example embodiment of the invention;
FIG. 6 shows a schematic diagram of a power cell according to another example embodiment of the invention;
fig. 7 shows a schematic diagram of a power cell with a diode according to another exemplary embodiment of the invention.
Detailed Description
Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The drawings are merely schematic illustrations of the invention and are not necessarily drawn to scale.
Further, as used herein, "coupled" may mean that two or more elements are in direct physical or electrical contact with each other, or in indirect physical or electrical contact with each other, or that two or more elements operate or act with each other.
Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, steps, and so forth. In other instances, well-known structures, methods, implementations, or operations are not shown or described in detail to avoid obscuring aspects of the invention.
Some of the block diagrams shown in the figures are functional entities and do not necessarily correspond to physically or logically separate entities. These functional entities may be implemented in one or more hardware modules or integrated circuits or in different networks and/or processor means and/or microcontroller means.
The invention aims to disclose a power unit, which comprises: a DC/DC conversion circuit; a bypass circuit, comprising: the DC/DC conversion circuit comprises a mechanical switch unit, an impedance network and a semiconductor switch unit, wherein the semiconductor switch unit and the impedance network are connected in series to form a series branch, a first end of the mechanical switch unit and a positive end of one side of the DC/DC conversion circuit are electrically connected with a positive end of one side of the power unit, and a second end of the mechanical switch unit, a second end of the series branch and a negative end of one side of the DC/DC conversion circuit are electrically connected with a negative end of one side of the power unit; the detection unit is used for detecting a working signal of the DC/DC conversion circuit and generating a detection signal according to the working signal; and the control unit is used for receiving and judging whether the DC/DC conversion circuit has a fault according to the detection signal, and when the DC/DC conversion circuit has the fault, the control unit outputs a first closing control signal to the control end of the mechanical switch unit and outputs a second closing control signal to the control end of the semiconductor switch unit so that the semiconductor switch unit is closed before the mechanical switch unit. The bypass circuit topology of the power unit effectively restrains current impact generated in bypass through the impedance network; in addition, the topology of the bypass circuit is applied to the DC/DC conversion occasion, and the effect that the bypass of the fault DC/DC conversion circuit can be maintained even if the auxiliary power supply is power-off is realized while the rapidity of the bypass action is realized by using the semiconductor switch; the current is switched to the mechanical switch unit after bypassing, and the loss of a bypass circuit is small. Further, the current surge generated in the circuit during the bypass process is smaller by adding a diode.
The power cell of the present invention is described in detail below with reference to fig. 2-7, wherein fig. 2 shows a schematic diagram of a power cell according to an example embodiment of the present invention; FIG. 3 shows a schematic diagram of a DC/DC conversion system incorporating a power cell of an exemplary embodiment of the present invention; FIG. 4 shows a schematic diagram of a power cell with a diode according to an example embodiment of the invention; FIG. 5 shows a schematic diagram of another power cell with a diode according to an example embodiment of the invention; FIG. 6 shows a schematic diagram of a power cell according to another example embodiment of the invention; fig. 7 shows a schematic diagram of a power cell with a diode according to another exemplary embodiment of the invention.
Fig. 2 shows a schematic diagram of a power cell according to an example embodiment of the invention. As shown in fig. 2, the power unit includes: the DC/DC conversion circuit 5 and the bypass circuit 1 are respectively connected with the DC/DC conversion circuit 1, wherein the bypass circuit 1 comprises a mechanical switch unit K, an impedance network Z and a semiconductor switch unit Q, the semiconductor switch unit Q and the impedance network Z are connected in series to form a series branch, the first end of the mechanical switch unit K, the positive end of one side of the DC/DC conversion circuit 5 and the positive end of one side of the power unit are electrically connected, and the first end of the series branch, the first end of the mechanical switch unit K, the positive end of one side of the DCThe second end of the mechanical switch unit K, the second end of the series branch, the negative end of the side of the DC/DC conversion circuit 5 and the negative end of the side of the power unit are electrically connected; a detection unit 2 for detecting a working signal of the DC/DC conversion circuit 5 and generating a detection signal according to the working signal; and a control unit 3, configured to receive the detection signal and determine whether the DC/DC conversion circuit 5 has a fault according to the detection signal, and when the DC/DC conversion circuit 5 has a fault, the control unit outputs a first close control signal to the control terminal of the mechanical switch unit K and outputs a second close control signal to the control terminal of the semiconductor switch unit Q, so that the semiconductor switch unit Q is closed before the mechanical switch unit K. The types of faults of the DC/DC conversion circuit 5 include overvoltage faults, undervoltage faults, overcurrent faults, or overtemperature faults. Wherein one side voltage of the power unit can be represented as VDC1And the voltage on the other side can be represented as VDC2Wherein one side of the power unit may be an input side and the other side may be an output side, but not limited thereto.
According to an exemplary embodiment of the invention, the power unit further comprises an auxiliary power supply 4 for supplying electrical energy to said detection unit and to the control unit.
According to an exemplary embodiment of the present invention, the DC/DC conversion circuit comprises a DC bus capacitor C, wherein a positive terminal of the DC bus capacitor C is electrically connected to a positive terminal of the one side of the DC/DC conversion circuit 5, and a negative terminal of the DC bus capacitor C is electrically connected to a negative terminal of the one side of the DC/DC conversion circuit 5.
Specifically, fig. 3 shows a schematic diagram of a DC/DC conversion system including power units according to the exemplary embodiment of the present invention, the system is a DC/DC conversion system having a serial structure, the system has N (N ≧ 1) power units (1#, 2# … N #), in the DC/DC conversion system having the serial structure as shown in fig. 3, the detection unit 2 in each power unit samples the input voltage, the output voltage, the input current, the output current, the temperature and any other form of working signals of the DC/DC conversion circuit 5 through, for example, a sampling circuit, and generates a detection signal according to the detected working signal, the control unit 3 can be various hardware, software, firmware and their combination, such as a DSP, an FPGA, an analog control chip and the like, the control unit 3 determines whether the DC/DC conversion circuit 5 has a fault according to the received detection signal, when the DC/DC conversion circuit 5 has a fault, for example, an overvoltage fault, an undervoltage fault, an overcurrent fault, or an overtemperature fault, the control unit 3 will send a first closing control signal to the control terminal of the mechanical switch unit K and output a second closing control signal to the control terminal of the semiconductor switch unit Q. The first close control signal and the second close control signal may be sent to the semiconductor switch unit Q and the mechanical switch unit K at the same time, or may be sent to the semiconductor switch unit Q and the mechanical switch unit K sequentially (for example, the control unit 3 may output the second close control signal first, and output the first close control signal after delaying the first predetermined time, or the control unit 3 may output the first close control signal first, and output the second close control signal after delaying the second predetermined time, where the close time required by the mechanical switch unit K is longer than the second predetermined time), but it is finally ensured that the semiconductor switch unit Q is closed rapidly first, and the mechanical switch unit K is closed in a delayed manner. After the semiconductor switch unit Q is closed, the voltage between the positive end and the negative end of one side of the DC/DC conversion circuit 5 is suddenly changed, the direct current bus capacitor C of the fault DC/DC conversion circuit discharges through the series branch of the bypass circuit, other DC/DC conversion circuits charge the corresponding direct current bus capacitor C through the series branch, and the current impact generated by each DC/DC conversion circuit 5 is limited by the impedance network Z on the series branch; and then the mechanical switch unit K is closed again and is kept in a closed state all the time, and the bypass current of the fault DC/DC conversion circuit is converted to the mechanical switch unit K from the series branch circuit, so that the bypass of the fault DC/DC conversion circuit is completed.
The bypass circuit topology of the power unit shown in fig. 2 effectively suppresses current surge generated by the dc bus capacitor during bypass; in addition, in the bypass circuit topology, in the DC/DC conversion occasion, the semiconductor switch is utilized to realize the rapidity of the bypass action and simultaneously realize the effect of maintaining the bypass of the faulty DC/DC conversion circuit even if the auxiliary power supply is out of power; and after bypassing, the current is converted to the mechanical switch unit K, so that the loss of a bypass circuit is small.
According to an exemplary embodiment of the present invention as shown in fig. 4, the
According to an exemplary embodiment of the present invention as shown in fig. 5, the
That is, the position of the diode is not particularly limited, and the current surge generated in the circuit during the bypass process can be reduced.
According to an example embodiment of the present invention, when the power unit is in a fault state, the control unit is further configured to output a shutdown control signal for controlling the DC/DC conversion circuit 5 to stop operating.
According to an exemplary embodiment of the present invention, wherein the mechanical switch unit K is constituted by a single mechanical switch, or by a plurality of mechanical switches connected in series or in parallel.
According to an example embodiment of the present invention, the impedance network Z is a resistor, an inductor, or a capacitor, or a series-parallel structure of a resistor, a capacitor, and an inductor.
According to an exemplary embodiment of the present invention, wherein the semiconductor switching unit Q is constituted by a single semiconductor switch, or by a plurality of semiconductor switches connected in series or in parallel.
It should be noted that the DC/DC conversion system shown in fig. 3 is only a specific embodiment to which the power unit of the present invention is applied, and here, the specific operation process of the bypass circuit of the power unit of the present invention is described in detail only by taking the system as an example, the bypass circuit topology of the power unit of the present invention is not limited to the above system, but is applicable to any DC/DC conversion system having a series structure, for example, the auxiliary power source may be inside each power unit, or a plurality of power units may share one auxiliary power source; similarly, the control unit and the detection unit may be provided in each power converter, or a plurality of power converters may share one control unit or detection unit, and an exemplary embodiment in which a plurality of power converters share one control unit or detection unit will be described below with reference to fig. 6.
FIG. 6 shows a schematic representation of a system according to the inventionA schematic diagram of a power cell of another example embodiment. As shown in fig. 6, the power unit includes: a plurality of power converters (N ≧ 1), 1#, 2# … N #) having one side connected in series to form one side (e.g., V) of the power cellDC1Side), each of said power converters comprising a DC/DC conversion circuit 5, a bypass circuit 1, each bypass circuit comprising: the power converter comprises a mechanical switch unit K, an impedance network Z and a semiconductor switch unit Q, wherein the semiconductor switch unit Q and the impedance network Z are connected in series to form a series branch, a first end of the mechanical switch unit K and a positive end of one side of the DC/DC conversion circuit 5 are electrically connected with a positive end of the corresponding side of the power converter, and a second end of the mechanical switch unit K, a second end of the series branch and a negative end of the one side of the DC/DC conversion circuit 5 are electrically connected with a negative end of the corresponding side of the power converter; the detection unit 2 is used for detecting working signals of the plurality of DC/DC conversion circuits, generating corresponding detection signals according to the working signals and transmitting the detection signals to the control unit; and a control unit 3, configured to receive and determine whether one or more of the DC/DC conversion circuits of the power converter has a fault according to the detection signal, and when one or more of the DC/DC conversion circuits has a fault, the control unit outputs a corresponding first close control signal to the control terminal of the mechanical switch unit K of the corresponding power converter and outputs a corresponding second close control signal to the control terminal of the semiconductor switch unit Q of the corresponding power converter, so that the semiconductor switch unit Q is closed before the mechanical switch unit K. Wherein the side voltage of the power unit can be represented as VDC1And the voltage on the other side can be represented as VDC2。
Similar to the bypass circuit topology of the power unit shown in fig. 2, the bypass circuit topology of the power unit shown in fig. 6 can also effectively suppress the current surge generated by the dc bus capacitor when bypassing; in addition, in the bypass circuit topology, in the DC/DC conversion occasion, the semiconductor switch is utilized to realize the rapidity of the bypass action and simultaneously realize the effect of maintaining the bypass of the faulty DC/DC conversion circuit even if the auxiliary power supply is out of power; and after bypassing, the current is converted to the mechanical switch unit K, so that the loss of a bypass circuit is small.
According to an exemplary embodiment of the invention, the power unit further comprises an auxiliary power supply 4 for supplying power to said
According to an exemplary embodiment of the present invention, the DC/DC conversion circuit 5 comprises a DC bus capacitor C, wherein a positive terminal of the DC bus capacitor C is electrically connected to a positive terminal of the one side of the DC/DC conversion circuit 5, and a negative terminal of the DC bus capacitor C is electrically connected to a negative terminal of the one side of the DC/DC conversion circuit 5.
According to an exemplary embodiment of the present invention as shown in fig. 7, the DC/DC converter circuit 5 comprises a DC bus capacitor C, and the bypass circuit further comprises a diode D, wherein an anode of the diode D is connected to the first end of the series branch and a cathode of the diode D is connected to a positive end of the DC bus capacitor C.
According to an exemplary embodiment of the present invention (not shown), the DC/DC converter circuit 5 comprises a DC bus capacitor C, and the bypass circuit further comprises a diode D, wherein an anode of the diode D is connected to a negative terminal of the DC bus capacitor C, and a cathode of the diode D is connected to the second terminal of the series branch.
That is, the position of the diode is not particularly limited, and the current surge generated in the circuit during the bypass process can be reduced.
According to an example embodiment of the present invention, the control unit 3 outputs said first closing control signal and said second closing control signal simultaneously.
According to an example embodiment of the present invention, the control unit 3 outputs the second close control signal first, delays for a first predetermined time and then outputs the first close control signal; or, the control unit 3 outputs the first closing control signal first, delays a second predetermined time, and then outputs the second closing control signal, wherein the closing time required by the mechanical switch unit K is longer than the second predetermined time.
According to an example embodiment of the present invention, when one or more of the DC/DC conversion circuits malfunctions, and the control unit 3 outputs a shutdown control signal so that the malfunctioning DC/DC conversion circuit stops operating.
According to an exemplary embodiment of the present invention, wherein the mechanical switch unit K is constituted by a single mechanical switch, or by a plurality of mechanical switches connected in series or in parallel.
According to an example embodiment of the present invention, the impedance network Z is a resistor, an inductor, or a capacitor, or a series-parallel structure of a resistor, a capacitor, and an inductor.
According to an exemplary embodiment of the present invention, wherein the semiconductor switching unit Q is constituted by a single semiconductor switch, or by a plurality of semiconductor switches connected in series or in parallel.
From the above detailed description, those skilled in the art will readily appreciate that a power unit according to an exemplary embodiment of the present invention has one or more of the following advantages.
According to some embodiments of the invention, the bypass circuit topology of the power unit effectively suppresses current surge generated in bypassing through the impedance network; in addition, in the bypass circuit topology, in the DC/DC conversion occasion, the semiconductor switch is utilized to realize the rapidity of the bypass action and simultaneously realize the effect of maintaining the bypass of the faulty DC/DC conversion circuit even if the auxiliary power supply is out of power; after bypassing, the current is converted to the mechanical switch unit, and the loss of a bypass circuit is small.
According to some embodiments of the present invention, the present invention further enables a smaller current surge to be generated in the circuit during the bypass process by adding a diode.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
It will be understood that the invention is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.
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