Novel solid-state AC circuit breaker suitable for distribution network
阅读说明：本技术 一种适用于配电网的新型固态交流断路器 (Novel solid-state AC circuit breaker suitable for distribution network ) 是由 李振伟 王晶 赵天翊 赵树军 单保涛 陶陈彬 马隽 于 2021-08-17 设计创作，主要内容包括：本发明公开了一种适用于配电网的新型固态交流断路器,包括主电路模块和辅助模块两部分；所述主电路模块包括二极管模块1、二极管模块2、二极管模块3、二极管模块4、IGBT模块和金属氧化物压敏电阻缓冲支路；所述辅助模块包括测量模块以及控制与驱动模块,所述控制与驱动模块电连接电连接IGBT模块,负责控制驱动断路器动作；所述测量模块电连接IGBT模块,负责测量驱动断路器动作产生的电流值和电压值。本发明基于IGBT快速开断的特性设计了一种纯电力电子元件组成的断路器,大大提高了开断电流的速度。该断路器能够在短时间内快速开断电路,而且增加的均压电路和吸收回路能够有效地吸收回路中出现的冲击使断路器稳定运行在安全区域。(The invention discloses a novel solid-state alternating current circuit breaker applicable to a power distribution network, which comprises a main circuit module and an auxiliary module; the main circuit module comprises a diode module 1, a diode module 2, a diode module 3, a diode module 4, an IGBT module and a metal oxide piezoresistor buffer branch circuit; the auxiliary module comprises a measuring module and a control and drive module, the control and drive module is electrically connected with the IGBT module and is responsible for controlling the action of the driving circuit breaker; the measuring module is electrically connected with the IGBT module and is responsible for measuring the current value and the voltage value generated by the action of the driving circuit breaker. The circuit breaker composed of the pure electric electronic elements is designed based on the characteristic that the IGBT is rapidly switched on and off, and the speed of switching on and off current is greatly improved. The circuit breaker can quickly break a circuit in a short time, and the added voltage equalizing circuit and the absorption loop can effectively absorb impact occurring in the loop so that the circuit breaker stably operates in a safe area.)
1. The utility model provides a novel solid-state AC circuit breaker suitable for distribution network which characterized in that: the device comprises a main circuit module and an auxiliary module;
the main circuit module comprises a diode module 1, a diode module 2, a diode module 3, a diode module 4, an IGBT module and a metal oxide piezoresistor buffer branch circuit; the diode module 1, the diode module 2, the diode module 3 and the diode module 4 are connected in series; one end of the IGBT module is connected to a circuit between the diode module 1 and the diode module 2, and the other end of the IGBT module is connected to a circuit between the diode module 3 and the diode module 4; the metal oxide piezoresistor buffer branch is connected in parallel to the IGBT module;
the auxiliary module comprises a measuring module and a control and drive module, the control and drive module is electrically connected with the IGBT module and is responsible for controlling the action of the driving circuit breaker; the measuring module is electrically connected with the IGBT module and is responsible for measuring the current value and the voltage value generated by the action of the driving circuit breaker.
2. A novel solid state ac circuit breaker adapted for use in a power distribution network, according to claim 1, wherein: and a voltage equalizing circuit which is connected with a plurality of IGBT modules in series is arranged in the main circuit module.
3. A new solid state ac circuit breaker adapted for use in a power distribution network, according to claim 2, wherein: the voltage-sharing circuit adopts an improved RCD voltage-sharing circuit;
the improved RCD voltage-sharing circuit comprises voltage-sharing branch circuits, the number of which is equal to that of the IGBT modules; each voltage-sharing branch comprises a C-D circuit formed by serially connecting a buffer capacitor C and a diode D, a static voltage-sharing resistor Rt formed by serially connecting a resistor R1 and a resistor R2, and a thyristor Q with one end electrically connected between the buffer capacitor C and the diode D and the other end electrically connected between a resistor R1 and a resistor R2; the C-D circuit is connected in parallel with two ends of the IGBT module, and the static voltage-sharing resistor Rt is connected in parallel with two ends of the IGBT module;
the thyristors Q are sequentially communicated in series.
4. A novel solid state ac circuit breaker adapted for use in a power distribution network, according to claim 1, wherein: the output end of the control and drive module is connected with the grid of the IGBT module, and sends a uniform drive signal to control the plurality of IGBT modules to be switched on and off simultaneously.
5. The novel solid state ac circuit breaker of claim 4, adapted for use in a power distribution network, characterized in that: the measuring module comprises a current transformer and a measuring instrument, the current of each IGBT branch is monitored in real time, and when the current is found to be over-current, a warning signal is sent to the control and driving module and over-current protection measures are taken.
6. The novel solid state ac circuit breaker of claim 5, adapted for use in a power distribution network, characterized in that: the auxiliary module further comprises a cooling device fixedly installed at the outer side of the main circuit module, and the cooling device adopts a water-cooling heat dissipation exchanger.
7. A novel solid state ac circuit breaker adapted for use in a power distribution network, according to claim 3, wherein: the improved RCD voltage-sharing circuit is divided into a dynamic voltage-sharing circuit and a static voltage-sharing circuit according to functions;
the dynamic voltage-sharing circuit part in the RCD circuit consists of a diode, a capacitor, a thyristor and a resistor, and the capacitor is charged by the C-D circuit at the turn-off moment to play a role in turn-off buffering; after the IGBT module is switched on, the thyristor Q is switched on for a period of time to form a C-Q-R annular passage to discharge the capacitor, so that preparation is made for next switching-off buffering.
8. A novel solid state ac circuit breaker adapted for use in a power distribution network as claimed in claim 7, wherein: the static voltage-sharing resistor selection process comprises the following steps: in order to realize voltage-sharing balance, a static voltage-sharing resistor Rt is connected in parallel at two ends of a leakage resistor, so that the equivalent resistance of each leakage resistor after being connected with the Rt in parallel is basically equal, and the equivalent resistance is an equivalent circuit of the former;
after Rt is increased, the voltage-sharing unbalance rate is within 5 percent, the voltage-sharing balance of each element can be ensured, and the value range of Rt is obtained; defining the voltage-sharing unbalance rate as the ratio of the highest voltage to the lowest voltage difference and the highest voltage borne in the series IGBT
Wherein, gamma is the voltage-sharing unbalance rate; vmax and Vmin are respectively the maximum and minimum values of the voltage at the two ends of the series IGBT;
assuming that the voltage borne by the IGBT1 is the largest and the voltage borne by the IGBT2 is the smallest among the n series IGBTs, the voltage-sharing unevenness after the parallel static voltage-sharing resistors is:
the value range of the static voltage-sharing resistance can be obtained according to the condition that gamma is less than or equal to 5 percent:
in the formula, Rt is static voltage equalizing resistance; roff1 is the equivalent drain resistance of IGBT 1; roff2 is the equivalent drain resistance of IGBT 2; the leakage resistance can be determined from the product parameters:
where Vces is the collector-emitter blocking voltage; ices is the collector-emitter leakage current.
9. A novel solid state ac circuit breaker adapted for use in a power distribution network as claimed in claim 8, wherein: voltage-sensitive voltage U of metal oxide voltage-sensitive resistor buffer branch circuitNMOVEqual to the maximum withstand voltage of IGBT
UNMOV＝VCE (17)
In the formula of UNMOVVoltage-dependent voltage, V, of a metal oxide varistor buffer branchCEThe maximum withstand voltage of the IGBT.
10. A novel solid state ac circuit breaker adapted for use in a power distribution network as claimed in claim 8, wherein: in order to verify the breaking capacity and speed of the solid-state alternating current circuit breaker, a solid-state circuit breaker model is built by using Pspie software according to element selection and parameter design of the circuit breaker, and an alternating current power distribution network with short-circuit current is subjected to switching-on and switching-off simulation tests.
Technical Field
The invention relates to a novel solid-state alternating current circuit breaker suitable for a power distribution network, and belongs to the technical field of circuit breakers.
Background
With the development of new energy technology, wind power, solar distributed generation and a large number of power electronic components are connected to an alternating current power distribution network, and in order to timely and quickly cut off a fault line after a short-circuit fault occurs in the line and protect power electronic equipment in the power grid, a circuit breaker capable of being quickly, flexibly and reliably cut off is urgently researched.
Recent advances in power semiconductor devices and their control technologies have facilitated the widespread use of power electronics technology in power systems, where research into solid state circuit breakers and hybrid circuit breakers based on power electronics components has received increasing attention.
The existing document 1 proposes a solid-state ac circuit breaker with a novel topology structure capable of reclosing and reclosing, wherein the circuit breaker uses a semi-controlled device power thyristor (SCR) as a switching-off element, so that the current must cross zero to be switched off, and the switching-off speed is slow and inflexible; the existing document 2 designs a solid-state ac circuit breaker formed by two IGBT circuits connected in reverse series, which can rapidly open and close an ac circuit without arcing, but when current flows in the forward and reverse directions, one branch is always idle and has no current, resulting in low utilization rate of elements; the existing document 3 designs a solid-state direct-current circuit breaker based on a silicon carbide type emitter turn-off thyristor, which has the advantages of strong capability of turning off large current of medium voltage level and the disadvantages of complex driving circuit and high driving power.
Disclosure of Invention
The technical problem to be solved by the invention is to provide the solid-state circuit breaker based on the insulated gate bipolar transistor, which can rapidly cut off the circuit of the alternating current power distribution network without arc, has a certain fault self-checking function and overcurrent protection capability, and overcomes the defect of low cutting-off speed of a mechanical circuit breaker.
In order to solve the problems, the technical scheme adopted by the invention is as follows:
a novel solid-state alternating current circuit breaker suitable for a power distribution network comprises a main circuit module and an auxiliary module;
the main circuit module comprises a diode module 1, a diode module 2, a diode module 3, a diode module 4, an IGBT module and a metal oxide piezoresistor buffer branch circuit; the diode module 1, the diode module 2, the diode module 3 and the diode module 4 are connected in series; one end of the IGBT module is connected to a circuit between the diode module 1 and the diode module 2, and the other end of the IGBT module is connected to a circuit between the diode module 3 and the diode module 4; the metal oxide piezoresistor buffer branch is connected in parallel to the IGBT module;
the auxiliary module comprises a measuring module and a control and drive module, the control and drive module is electrically connected with the IGBT module and is responsible for controlling the action of the driving circuit breaker; the measuring module is electrically connected with the IGBT module and is responsible for measuring the current value and the voltage value generated by the action of the driving circuit breaker.
As a further improvement of the invention, a voltage equalizing circuit which is connected with a plurality of IGBT modules in series is arranged in the main circuit module. As a further improvement of the invention, the voltage-sharing circuit adopts an improved RCD voltage-sharing circuit;
the improved RCD voltage-sharing circuit comprises voltage-sharing branch circuits, the number of which is equal to that of the IGBT modules; each voltage-sharing branch comprises a C-D circuit formed by serially connecting a buffer capacitor C and a diode D, a static voltage-sharing resistor Rt formed by serially connecting a resistor R1 and a resistor R2, and a thyristor Q with one end electrically connected between the buffer capacitor C and the diode D and the other end electrically connected between a resistor R1 and a resistor R2;
the C-D circuit is connected in parallel with two ends of the IGBT module, and the static voltage-sharing resistor Rt is connected in parallel with two ends of the IGBT module; the thyristors Q are sequentially communicated in series.
As a further improvement of the invention, the output end of the control and drive module is connected with the grid of the IGBT module, and a uniform drive signal is sent to control the on-off of the plurality of IGBT modules at the same time.
As a further improvement of the invention, the measuring module comprises a current transformer and a measuring instrument, the current of each IGBT branch is monitored in real time, and when the overcurrent is found, a warning signal is sent to the control and drive module and overcurrent protection measures are taken.
As a further improvement of the present invention, the auxiliary module further includes a cooling device fixedly installed at an outer side portion of the main circuit module, and the cooling device employs a water-cooling heat-dissipation exchanger.
As a further improvement of the invention, the improved RCD voltage-sharing circuit is divided into a dynamic voltage-sharing circuit and a static voltage-sharing circuit according to functions;
the dynamic voltage-sharing circuit part in the RCD circuit consists of a diode, a capacitor, a thyristor and a resistor, and the capacitor is charged by the C-D circuit at the turn-off moment to play a role in turn-off buffering; after the IGBT module is switched on, the thyristor Q is switched on for a period of time to form a C-Q-R annular passage to discharge the capacitor, so that preparation is made for next switching-off buffering.
As a further improvement of the invention, the static equalizing resistance selection process comprises the following steps: in order to realize voltage-sharing balance, a static voltage-sharing resistor Rt is connected in parallel at two ends of a leakage resistor, so that the equivalent resistance of each leakage resistor after being connected with the Rt in parallel is basically equal, and the equivalent resistance is an equivalent circuit of the former;
after Rt is increased, the voltage-sharing unbalance rate is within 5 percent, the voltage-sharing balance of each element can be ensured, and the value range of Rt is obtained; defining the voltage-sharing unbalance rate as the ratio of the highest voltage to the lowest voltage difference and the highest voltage borne in the series IGBT
Wherein, gamma is the voltage-sharing unbalance rate; vmax and Vmin are respectively the maximum and minimum values of the voltage at the two ends of the series IGBT; assuming that the voltage borne by the IGBT1 is the largest and the voltage borne by the IGBT2 is the smallest among the n series IGBTs, the voltage-sharing unevenness after the parallel static voltage-sharing resistors is:
the value range of the static voltage-sharing resistance can be obtained according to the condition that gamma is less than or equal to 5 percent:
in the formula, Rt is static voltage equalizing resistance; roff1 is the equivalent drain resistance of IGBT 1; roff2 is the equivalent drain resistance of IGBT 2;
the leakage resistance can be determined from the product parameters:
where Vces is the collector-emitter blocking voltage; ices is the collector-emitter leakage current.
As a further improvement of the invention, the voltage-dependent voltage U of the metal oxide voltage-dependent resistor buffer branch circuitNMOVEqual to the maximum withstand voltage of IGBT
UNMOV＝VCE (17)
In the formula of UNMOVVoltage-dependent voltage, V, of a metal oxide varistor buffer branchCEThe maximum withstand voltage of the IGBT.
As a further improvement of the invention, in order to verify the breaking capacity and speed of the solid-state alternating current circuit breaker, a solid-state circuit breaker model is built by using Pspie software according to element selection and parameter design of the circuit breaker, and an on/off simulation test is carried out on an alternating current power distribution network with short-circuit current.
Adopt the produced beneficial effect of above-mentioned technical scheme to lie in:
the invention selects the IGBT element as the on-off element, so that the circuit breaker has the advantages of high on-off speed, no arc, simple driving structure and the like. The topological structure has high utilization rate of elements, half of IGBT elements can be saved compared with the topological structure in a solid-state alternating current circuit breaker formed by two IGBT circuits in an anti-series connection mode, and cost is greatly reduced. In order to effectively solve the problems of IGBT peak voltage and series connection voltage-sharing unbalance caused in the on-off process of the circuit breaker, an improved RCD voltage-sharing circuit is designed. A16.3 kV/347MVA solid-state alternating current circuit breaker model is built by using a Pspice platform, and a breaking simulation test is carried out in a power distribution network environment, and the test result proves that the circuit breaker is high in breaking speed, small in overvoltage and good in breaking effect.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed for the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.
Figure 1 is a schematic diagram of a circuit breaker structural module;
FIG. 2 is a schematic diagram of a voltage equalizing circuit of series IGBTs;
FIG. 3 is a schematic diagram of the operating principle of the improved RCD circuit;
FIG. 4 is a diagram of breaker open-circuit voltage and current waveforms;
fig. 5 is a diagram showing waveforms of closing voltage and current of the circuit breaker.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the application, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.
The relative arrangement of the components and steps, the numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present application unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting.
Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.
In the description of the present application, it is to be understood that the orientation or positional relationship indicated by the directional terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc., are generally based on the orientation or positional relationship shown in the drawings, and are used for convenience of description and simplicity of description only, and in the case of not making a reverse description, these directional terms do not indicate and imply that the device or element being referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore, should not be considered as limiting the scope of the present application; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.
As shown in fig. 1, a novel solid-state ac circuit breaker suitable for a power distribution network includes two parts, a main circuit module and an auxiliary module;
the main circuit module comprises a diode module 1, a diode module 2, a diode module 3, a diode module 4, an IGBT module and a metal oxide piezoresistor buffer branch circuit; the diode module 1, the diode module 2, the diode module 3 and the diode module 4 are connected in series; one end of the IGBT module is connected to a circuit between the diode module 1 and the diode module 2, and the other end of the IGBT module is connected to a circuit between the diode module 3 and the diode module 4; the metal oxide piezoresistor buffer branch is connected in parallel to the IGBT module;
the auxiliary module comprises a measuring module and a control and drive module, the control and drive module is electrically connected with the IGBT module and is responsible for controlling the action of the driving circuit breaker; the measuring module is electrically connected with the IGBT module and is responsible for measuring the current value and the voltage value generated by the action of the driving circuit breaker.
Further, a voltage equalizing circuit is arranged in the main circuit module and is connected with a plurality of IGBT modules in series.
Further, in this embodiment, the voltage-sharing circuit is an improved RCD voltage-sharing circuit; the dynamic voltage-sharing function of the traditional RCD circuit can be exerted, and the static voltage-sharing effect can also be realized, and the schematic diagram is shown in figure 2.
The improved RCD voltage-sharing circuit comprises voltage-sharing branch circuits, the number of which is equal to that of the IGBT modules; each voltage-sharing branch comprises a C-D circuit formed by serially connecting a buffer capacitor C and a diode D, a static voltage-sharing resistor Rt formed by serially connecting a resistor R1 and a resistor R2, and a thyristor Q with one end electrically connected between the buffer capacitor C and the diode D and the other end electrically connected between a resistor R1 and a resistor R2;
the C-D circuit is connected in parallel with two ends of the IGBT module, and the static voltage-sharing resistor Rt is connected in parallel with two ends of the IGBT module; the thyristors Q are sequentially communicated in series.
Further, in this embodiment, the output end of the control and drive module is connected to the gate of the IGBT module, and sends a uniform drive signal to control the plurality of IGBT modules to be turned on and off simultaneously.
Further, in this embodiment, the measurement module includes a current transformer and a measurement instrument, and monitors the current of each IGBT branch in real time, and when an overcurrent is found, sends a warning signal to the control and drive module and takes an overcurrent protection measure.
Further, the auxiliary module further includes a cooling device fixedly installed at an outer side portion of the main circuit module, and the cooling device employs a water-cooling heat exchanger.
Further, the working principle of the improved RCD circuit is shown in fig. 3, and the improved RCD voltage-sharing circuit is divided into two parts, namely a dynamic voltage-sharing circuit and a static voltage-sharing circuit according to functions;
the dynamic voltage-sharing circuit part in the RCD circuit consists of a diode, a capacitor, a thyristor and a resistor, and the capacitor is charged by the C-D circuit at the turn-off moment to play a role in turn-off buffering; after the IGBT module is switched on, the thyristor Q is switched on for a period of time to form a C-Q-R annular passage to discharge the capacitor, so that preparation is made for next switching-off buffering.
Further, in this embodiment, the static equalizing resistance selecting process: in order to realize voltage-sharing balance, a static voltage-sharing resistor Rt is connected in parallel at two ends of a leakage resistor, so that the equivalent resistance of each leakage resistor after being connected with the Rt in parallel is basically equal, and the equivalent resistance is an equivalent circuit of the former;
after Rt is increased, the voltage-sharing unbalance rate is within 5 percent, the voltage-sharing balance of each element can be ensured, and the value range of Rt is obtained; defining the voltage-sharing unbalance rate as the ratio of the highest voltage to the lowest voltage difference and the highest voltage borne in the series IGBT
Wherein, gamma is the voltage-sharing unbalance rate; vmax and Vmin are respectively the maximum and minimum values of the voltage at the two ends of the series IGBT; assuming that the voltage borne by the IGBT1 is the largest and the voltage borne by the IGBT2 is the smallest among the n series IGBTs, the voltage-sharing unevenness after the parallel static voltage-sharing resistors is:
the value range of the static voltage-sharing resistance can be obtained according to the condition that gamma is less than or equal to 5 percent:
in the formula, Rt is static voltage equalizing resistance; roff1 is the equivalent drain resistance of IGBT 1; roff2 is the equivalent drain resistance of IGBT 2;
the leakage resistance can be determined from the product parameters:
where Vces is the collector-emitter blocking voltage; ices is the collector-emitter leakage current.
This example illustratesIn one step, the voltage-dependent voltage U of the metal oxide voltage-dependent resistor buffer branch circuitNMOVEqual to the maximum withstand voltage of IGBT
UNMOV＝VCE (17)
In the formula of UNMOVVoltage-dependent voltage, V, of a metal oxide varistor buffer branchCEThe maximum withstand voltage of the IGBT.
Further, in order to verify the breaking capacity and speed of the solid-state alternating current circuit breaker, a solid-state circuit breaker model is built by using Pspie software according to element selection and parameter design of the circuit breaker, and an alternating current power distribution network with short-circuit current is subjected to switching-on and switching-off simulation tests.
Specifically, in the embodiment, a 16.3kV/347MVA solid-state circuit breaker model is built by using Pspice software, and the 10kV alternating-current distribution network with 20kA of short-circuit current is switched on and switched off. Simulated waveforms of the voltage across the circuit breaker and the current through the circuit breaker are shown in fig. 4 and 5.
Fig. 4 shows the voltage across the circuit breaker and the current through the circuit breaker during the opening process, from which it can be seen that the distribution network is short-circuited at 3.3ms, and then the short-circuit current is increased sharply to 20 kA. The breaker sends an opening instruction at the moment of 5ms, after 0.3ms delay starting action, the current begins to decline, the current drops to 0 at the moment of 6.4ms, the breaker is completely disconnected at the moment, the opening process lasts for 1.4ms, the voltage at two ends of the breaker has 121V conduction voltage loss before opening, a 16kV peak voltage is generated in the opening process, and finally the voltage tends to be stable.
Fig. 5 shows waveforms of voltage and current in a closing process of the circuit breaker, and it is easy to see from the figure that the circuit breaker sends a closing instruction at a time of 5ms, the circuit breaker starts to operate at a time of 5.3ms, a voltage drop is 118V (an on-state voltage drop of the circuit breaker) at a time of 5.4ms, the current is restored to 19kA at a time of 5.8ms, and the circuit breaker completes closing and takes 0.8 ms.
In summary, the switching-off time of the circuit breaker is 1.4ms, the switching-on time of the circuit breaker is 0.8ms, the impulse voltage in the switching-off process is controlled within 16kV, the circuit breaker has certain voltage loss due to the saturation voltage existing in the power electronic elements inside the solid-state circuit breaker during working, the on-state voltage loss of the circuit breaker in the test is about 120V, and the voltage loss rate is 1.5%, which is still within the acceptable range. Taking a ZW32-12F type mechanical breaker as an example, the switching-on and switching-off time is generally 20-55 ms and 25-60 ms, and the voltage loss during switching-on is within 2V, so compared with the mechanical breaker, the voltage loss of the solid-state breaker is higher, but the switching-off speed is greatly improved, the overvoltage is effectively inhibited, and the switching-on and switching-off effects are better.
The circuit breaker composed of the pure electric electronic elements is designed on the basis of the characteristic that the IGBT is rapidly switched on and off, and the speed of switching on and off current is greatly improved. However, due to the fragility of power electronic components, the protection of the power electronic components is directly related to whether the circuit breaker can work reliably and durably, so that a voltage equalizing circuit and a absorbing circuit are arranged to prevent the IGBT from being damaged by overvoltage. A16.3 kV/347MVA solid-state circuit breaker model is built on a Pspice platform, and simulation tests are carried out on a 10 kV-class alternating-current distribution network circuit. The test result shows that the circuit breaker can be quickly opened and closed in a short time, and the added voltage equalizing circuit and the absorption loop can effectively absorb the impact generated in the loop so that the circuit breaker stably operates in a safe area.