TWI802142B - Dual-path switching high-speed electronic circuit breaker - Google Patents

Abstract

The invention relates to a dual-path switching high-speed electronic circuit breaker. Primarily, a current transformer of an electronic circuit breaker is connected to a power terminal, and an output end of the current transformer is connected to an amplifier. An output end of the amplifier is connected to a sub-controller, and the sub-controller has a built-in current overload detection circuit. The output end of current transformer is also connected to a dual SCR (Silicon Controlled Rectifier) circuit and a soft starting circuit, and an output end of the sub-controller is connected to the dual SCR circuit, the soft starting circuit and a main controller. An output end of the main controller is connected to the sub-controller, and the dual SCR circuit and the soft starting circuit are connected to a load which is also connected to the power terminal. After the soft start is over, the sub-controller triggers the dual SCR circuit to conduct, and the dual SCR circuit realizes the full waveguide function. Accordingly, not only can the surge current at startup be limited within the normal operating range, but also electrical equipment can be quickly disconnected from the mains in a shorter reaction time when there is an overload or short circuit. It can protect the electrical equipment or avoid the impact of regional power grid and has excellent stability, so as to increase the practicality and efficiency for the whole implementation.

Description

High-speed electronic circuit breaker with dual path switching

The present invention relates to a high-speed electronic circuit breaker with dual-path switching, in particular to a circuit breaker that can not only limit the surge current at start-up within the normal operating range, but also respond in a shorter time when overloaded or short-circuited. Quickly disconnect the electrical equipment from the mains within a short period of time, which can protect the electrical equipment or avoid the impact of the regional power grid, and has excellent stability, and has more practical features in its overall implementation and use.

By the way, with the rapid development of the power electronics industry, in many applications such as uninterruptible power supply [UPS], motor drive, electrical equipment, etc., the demand for overload protection is also growing rapidly; short circuit can be regarded as the most serious overload situation, the It can suddenly rise to more than 20 times the maximum rated current value, which means that the unexpected large current will far exceed the rated current of the semiconductor switching element, thereby immediately damaging the semiconductor switching element or equipment. This type of fault may occur from time to time in Anywhere in a device or circuit, if it happens on alternating current, a short circuit can affect power to the entire area, and on a battery power source such as direct current, a short circuit can overheat the battery in a short period of time and even cause a severe explosion.

Therefore, with the increase of electrical equipment, there are more and more protection devices. According to the Finnish national standard, fuses and circuit breakers are used for short-circuit protection in customer distribution circuits; fuses have the advantages of cheap price and small size, making fuses It is considered to be the simplest and cheapest protection device for interrupting fault current, but the fuse has obvious disadvantages. It is a one-time device, and in the UL248 or IEC127 specification, the fuse needs to be rated at twice the rated current at 1 The circuit breaker can improve the shortcomings of the fuse, and the circuit breaker has become an overload protection device widely used in industry. For this reason, the IEEE standard has issued the low-voltage used in industrial and commercial power systems recommended by IEEE since 2007. Application specification for circuit breakers.

The circuit breaker detects the overload of the current through the electric heating or electromagnetic device and the mechanical mechanism, but the internal mechanical device may fail over time, and in order to eliminate the arc generated by the mechanical switch, it is necessary to only use the arc elimination device to break the circuit In the device, the whole device is more complicated, plus the circuit breaker is based on a very slow-acting bimetallic lever and a trip mechanism, and its reaction time depends on the percentage of overload current of the fault, and the response is very slow when overloaded, and the reaction time of the low-voltage circuit breaker Usually it takes tens of milliseconds at least, resulting in equipment damage.

The reason is that, in view of this, the inventor has been adhering to many years of rich experience in design, development and actual production in this related industry, researched and improved the existing structure and defects, and provided a high-speed electronic circuit breaker with dual-path switching, in order to achieve better practicality purpose of value.

The main purpose of the present invention is to provide a high-speed electronic circuit breaker with dual-path switching, which can not only limit the inrush current at start-up to the normal operating range, but also can operate in a shorter period of time when overloaded or short-circuited. Within the reaction time, the electrical equipment can be quickly disconnected from the mains, which can protect the electrical equipment or avoid the impact of the regional power grid, and has excellent stability, and has more practical features in its overall implementation and use.

The main purpose and effect of the present invention with dual-path switching high-speed electronic circuit breaker are achieved by the following specific technical means:

Its main system includes electronic circuit breakers; among them:

In the electronic circuit breaker, the current transformer is connected to the power supply terminal, and an amplifier is connected to the output terminal of the current transformer. The output terminal of the amplifier is connected to a sub-controller, and the sub-controller has built-in current overload detection circuit, so that the output signal of the current transformer is amplified by the amplifier and then transmitted to the sub-controller, and the current overload detection circuit built in the sub-controller is used to detect whether the current is overloaded, and at the output terminal of the current transformer Also connected with dual SCR circuit and slow start circuit respectively, the dual SCR circuit is two Silicon Controlled Rectifiers [Silicon Controlled Rectifier, SCR] connected in reverse parallel, and the output terminal of the secondary controller is respectively connected with the dual SCR circuit , The slow start circuit is connected to the main controller, the slow start circuit is responsible for absorbing the surge current generated during startup, so that the output terminal of the main controller is connected to the secondary controller, and the dual SCR circuit and the slow start The circuit is connected to the load, and the load is also connected to the power supply terminal, so that after the slow start is over, the secondary controller triggers the conduction of the dual SCR circuit, and realizes the full-wave conduction function through the dual SCR circuit.

The present invention has a preferred embodiment of a dual-path switching high-speed electronic circuit breaker, wherein, when the electronic circuit breaker is applied to the three-phase power terminals, the three-phase power terminals are respectively connected to three groups of the electronic circuit breakers The current transformer of the circuit breaker, and the output terminals of the sub-controllers of the three sets of electronic circuit breakers are connected to the same main controller, and the output terminals of the main controller are respectively connected to the three sets of electronic circuit breakers. The secondary controller of the circuit breaker.

In order to have a more complete and clear disclosure of the technical content used in the present invention, the purpose of the invention and the effects achieved, it will be described in detail below, and please also refer to the disclosed drawings and drawing numbers:

First of all, please refer to the schematic diagram of the structure of the present invention shown in the first figure, the present invention mainly includes an electronic circuit breaker (1); wherein:

The electronic circuit breaker (1) connects the current transformer (11) to the power supply terminal (2), and the output terminal of the current transformer (11) is connected to an amplifier (12), and the output of the amplifier (12) A secondary controller (13) is connected to the terminal, and the secondary controller (13) has a built-in current overload detection circuit, so that the output signal of the current transformer (11) is amplified by the amplifier (12) and then transmitted to the secondary The controller (13) utilizes the built-in current overload detection circuit of the sub-controller (13) to detect whether the current is overloaded, and the output terminals of the current transformer (11) are also connected with dual SCR circuits (14) and Slow start circuit (15), the double SCR circuit (14) is two Silicon Controlled Rectifiers [Silicon Controlled Rectifier, SCR] connected in reverse parallel, and the output terminals of the secondary controller (13) are respectively connected to the double SCR circuit (14), the slow start circuit (15) and the main controller (16), the slow start circuit (15) is responsible for absorbing the surge current generated during startup, so that the output terminal of the main controller (16) and the The sub-controller (13) is connected, and the double SCR circuit (14) and the slow start circuit (15) are connected to the load (3), and the load (3) is also connected to the power supply terminal (2), After the end of the slow start, the secondary controller (13) triggers the conduction of the double SCR circuit (14), and realizes the full-wave conduction function through the double SCR circuit (14).

In addition, please refer to the second diagram of another embodiment of the present invention [three-phase power supply], the electronic circuit breaker (1) can also be applied to the three-phase power supply end (2), so that The power terminals (2) of the three phases are respectively connected to the current transformers (11) of the three groups of the electronic circuit breakers (1), and the sub-controllers (13) of the three groups of the electronic circuit breakers (1) are connected to each other. ) output terminals are all connected to the same main controller (16), and the output terminals of the main controller (16) are respectively connected to the sub-controllers (13) of the three groups of electronic circuit breakers (1).

］透過該電流互感器(11)輸出端轉換成微小的電流，再透過該放大器(12)將訊號放大，其訊號［

］傳送至該副控制器(13)內部的比較器判斷是否過載，當該電子式斷路器(1)啟動時，該副控制器(13)會先驅動該緩啟動電路(15)，之後再由該副控制器(13)觸發導通該雙SCR電路(14)，同時間立即關閉該緩啟動電路(15)。 When the electronic circuit breaker (1) is in use, it knows the working status of the secondary controller (13) through the signal of the dual SCR circuit (14), and the main controller (16) sends a reset signal To reply to the built-in SR flip-flop of the sub-controller (13), the DAC output (DAC+) and (DAC-) inside the main controller (16) are sent to the comparator in the sub-controller (13) as Voltage of current setting value, load current［

] Convert the output terminal of the current transformer (11) into a small current, and then amplify the signal through the amplifier (12), and the signal [

] sent to the internal comparator of the sub-controller (13) to determine whether it is overloaded, when the electronic circuit breaker (1) starts, the sub-controller (13) will drive the slow start circuit (15) first, and then The dual SCR circuit (14) is triggered to be turned on by the secondary controller (13), and at the same time, the slow start circuit (15) is immediately turned off.

Please also refer to the third figure as shown in the 2.5V high-precision reference voltage circuit diagram of the present invention. Since the operating voltage of the secondary controller (13) is between 0V and 5V, the current transformer (11) operates at the maximum rated current [50A], the current at the output end passes through the I-V amplifier circuit, and the output voltage at the output end is about -2.5V to 2.5V, so a voltage follower circuit composed of a high-precision 2.5V reference voltage source and an operational amplifier is provided to provide a A stable and precise 2.5V is used to clamp the output terminal voltage so that the voltage output falls between 0V and 5V.

合適，但由於7.8k

並非市面上常用規格，所以選擇較接近的電阻值7.5k

放大倍率，由下列公式(6)可以得知放大3.64倍。 Please refer to the fourth figure again, as shown in the amplifier circuit diagram of the present invention, the current detection is through the current transformer (11) of 1:1000, and the current signal is converted into a voltage signal by the sampling resistor, because the voltage signal changes The amount is too small for the sub-controller (13), so it must be amplified by the amplifier (12), the magnification is set through the RG gain resistor, and the signal is clamped to 2.5V, and then the signal is amplified and sent to the sub-controller (13). The magnification is based on the fact that the electronic circuit breaker (1) can be calculated at a rated current of 50A. In fact, the rated current of the circuit breaker is 45A, and 45A to 50A is reserved; it can be calculated by the following formula (1) The 50A root mean square value is converted into the maximum peak value, and the maximum current measured by the current transformer (11) of 1:1000 can be known by the following formula (2), because the inside of the secondary controller (13) cannot read Therefore, a 10-ohm resistor is used to convert the current signal into a voltage signal through Ohm's law. The following formula (3) is used to calculate the voltage of 50A through the current transformer (11) and sampled by the resistor is only 0.0707V. This voltage is too small for the controller (13), and the maximum voltage value should be 2.5V. The magnification is calculated through the following formula (4), and the signal is amplified through the amplifier (12), through the following formula (5) to calculate the RG resistance value should be 7.8k

fit, but due to 7.8k

It is not a common specification on the market, so choose a closer resistance value of 7.5k

The magnification can be obtained from the following formula (6) to magnify 3.64 times.

(1)

(1)

(2)

(2)

(3)

(3)

(4)

(4)

(5)

(5)

(6)

(6)

Please also refer to the fifth figure of the current overload detection circuit diagram of the present invention, the sub-controller (13) has a built-in current overload detection circuit, so that the current detected by the current transformer (11) passes through the amplifier (12) Input into I _in after amplification, because the direction of the alternating current is constantly changing, two comparators are used to detect whether the positive half-wave or negative half-wave current exceeds the DAC+ and DAC- sent by the main controller (16) Set value, if there is an overload, it will trigger the SR flip-flop through the OR gate, disconnect the conduction of the SCR, and wait for the main controller (16) to send a Reset signal before the SR flip-flop will start working again. When the flip-flop is reset, a signal is sent to turn on the SCR, causing the slow start circuit (15) to fail. Therefore, the AND gate is used to control the output of the SR flip-flop. When the slow start is over, the On signal is activated to make the SR flip-flop Signal output to turn on the SCR; the setting value of the DAC is generated by the built-in 10-Bit DAC of the main controller (16), and the magnification through the above formula (6) can be derived from the following formula (7) per ampere After the current passes through the current transformer (11) and the amplifier (12), it will output 0.051V, and the setting values of DAC+ and DAC- are passed through the following formula (8)(9), and the values in the following formula (8)(9) The 512 series is based on the central voltage of 2.5V, and the set value is added or decreased based on the central voltage.

(7)

(7)

(8)

(8)

(9)

(9)

會被強制通過NTC電阻達到抑制浪湧電流的效果；請再一併參閱第七圖本發明之TRIAC驅動電路圖所示，該副控制器(13)透過光耦合器去驅動TRIAC，讓該負載(3)之電流

能流通過NTC電阻；請再一併參閱第八圖本發明之TRAIC電流與SCR電流測量圖所示，綠色波形表示透過TRIAC電流流通NTC的電流，黃色波形表示流通SCR的電流，由波形可以確認出由緩啟動切換至SCR時電流不會有任何中斷之情形，可以確保設備供電不會停止。 Please refer to Figure 6 again, as shown in the slow start circuit diagram of the present invention, when the electronic circuit breaker (1) starts, the TRIAC of the slow start circuit (15) will be turned on first to allow the current to flow from the TRIAC to the NTC, because the NTC After the resistor is energized, the resistance value will gradually approach 0 ohms to achieve the effect of slow start. Since the long-term operation of the NTC will cause energy consumption, so after waiting for 2s, the SCR will be switched on to make the current flow to the SCR, and then the TRIAC will be disconnected to reduce Energy loss, only TRIAC will be turned on during slow start, so the load current

It will be forced to pass through the NTC resistor to achieve the effect of suppressing the surge current; please refer to the TRIAC drive circuit diagram of the present invention in the seventh figure, the sub-controller (13) drives the TRIAC through the optocoupler, so that the load ( 3) current

The energy flows through the NTC resistor; please refer to Figure 8, the TRAIC current and SCR current measurement diagram of the present invention, the green waveform indicates the current flowing through the NTC through the TRIAC current, and the yellow waveform indicates the current flowing through the SCR, which can be confirmed by the waveform There will be no interruption of current when switching from slow start to SCR, which can ensure that the power supply of the equipment will not stop.

Please also refer to the schematic diagram of the double SCR circuit of the present invention shown in Figure 9. Since the SCR can only be conducted in one direction, it is assembled into the double SCR circuit (14) that can be conducted in both directions through anti-parallel connection, and the secondary control The device (13) conducts the SCR through the optocoupler to quickly conduct or disconnect the power supply terminal (2).

The circuit performance of the electronic circuit breaker (1) is verified below, please refer to the schematic diagram of the test platform structure of the present invention in the tenth figure, which is to connect the electronic circuit breaker (1) to a commonly used load ( 3), such as: 1100W light bulbs, motors, ovens, hair dryers, etc., use these high-power electrical equipment loads (3) to simulate normal use, connect a 50A fuse in series to the single-phase 110V AC power supply, and then connect to the electronic circuit breaker (1) branch to supply power to each electrical equipment, and set a short circuit switch to simulate the short circuit of the equipment, and verify the electronic circuit breaker (1) Several important parameters are: slow start effect, response time and heat generated by SCR under different loads .

When the load (3) is a 3/4 hp single-phase motor, please also refer to Figure 11, as shown in the starting current waveform diagram of a 3/4 hp single-phase AC motor without slow start, the surge current when the power is started The maximum value is about 40A. Please refer to the twelfth figure together with the starting current waveform diagram of the slow start 3/4 hp single-phase AC motor. When the power is started, the maximum value of the surge current is about 11A, so that The starting circuit (15) can effectively reduce the surge current during starting by about 3.6 times. Please also refer to the thirteenth figure 3/4 single-phase AC motor current waveform diagram, the yellow waveform is the current waveform, the blue waveform is the output waveform of the current transformer through the amplification circuit, and the yellow waveform is set to 5A. , when the motor is running stably, the maximum current is about 9.5A, the blue waveform is set to a grid of 500mV, with 2.5V as the center point, when the motor is running stably, the maximum current is about 0.4V.

When the load (3) is a 1100W light bulb, please refer to Figure 14, as shown in the starting current waveform diagram of the 1100W light bulb without slow start. When the power supply starts, the maximum surge current is about 36A. Please refer to Figure 15 shows the starting current waveform diagram of a slow-start 1100W bulb. When the power supply starts, the maximum surge current is about 15A, so that the slow-start circuit (15) can effectively reduce the start-up surge current by about 2.4 times. Please also refer to the 16th figure 1100W bulb current waveform diagram, the yellow waveform is the current waveform, the blue waveform is the output waveform of the current transformer through the amplifier circuit, and the yellow waveform is set to 5A, when the current is stable The maximum value is about 13A, the blue waveform is set to a grid of 500mV, with 2.5V as the center point, and the maximum current value is about 0.45V when it is running stably. Please also refer to the 17th Figure 1100W bulb overload protection test waveform, the yellow waveform is the current waveform, and the blue waveform is the SCR drive signal. It can be known that the current will rise above 40A during a short circuit, and the SCR drive signal will It is turned off at the moment of short circuit, but the characteristics of SCR will turn off the conduction when the AC current crosses zero. This test is about 4ms to turn off the conduction.

When the load (3) is a 10A linear load [oven], please also refer to the 18th Figure 18 without slow start 10A linear load starting current waveform diagram. When the power supply starts, the maximum surge current is about 16A. Please also refer to Figure 19, which shows the slow start 10A linear load startup current waveform diagram. When the power supply starts, the maximum surge current is about 10A, so that the slow start circuit (15) can effectively reduce the startup time. The surge current is about 1.6 times. Please refer to the 20th Figure 10A linear load current waveform, the yellow waveform is the current waveform, the blue waveform is the output waveform of the current transformer through the amplifier circuit, and the yellow waveform is set to 10A. When it is running stably The maximum current is about 16A, the blue waveform is set to 500mV, with 2.5V as the center point, and the maximum current is about 0.55V when it is running stably. Please refer to the 21st Figure 10A linear load overload protection test waveform diagram. The yellow waveform is the current waveform, and the blue waveform is the SCR drive signal. It can be known that the current will rise above 40A when the short circuit occurs, and the SCR drive The signal will be turned off at the moment of short circuit, but the characteristics of SCR will turn off the conduction when the AC current crosses zero. This test is about 5ms to turn off the conduction.

When the load (3) is a 20A linear load [2 ovens], please also refer to Figure 22, as shown in the starting current waveform diagram of a 20A linear load without slow start. When the power supply starts, the maximum surge current is about It is 36A, please refer to the 23rd figure together with the slow start 20A linear load starting current waveform diagram, when the power supply is started, the maximum surge current is about 22A, so that the slow start circuit (15) can be effectively reduces the inrush current at start-up by about 1.6 times. Please also refer to the 24th Figure 20A linear load current waveform diagram, the yellow waveform is the current waveform, the blue waveform is the output waveform of the current transformer through the amplification circuit, and the yellow waveform is set to 10A. When it is running stably The maximum current is about 32A, the blue waveform is set to a grid of 500mV, with 2.5V as the center point, and the maximum current is about 1.1V when it is running stably. Please also refer to the 25th Figure 20A linear load overload protection test waveform diagram, the yellow waveform is the current waveform, and the blue waveform is the SCR drive signal. It can be known that the current will rise to more than 40A during a short circuit, and the SCR drive The signal will be turned off at the moment of short circuit, but the characteristics of SCR will turn off the conduction when the AC current crosses zero. This test is about 5ms to turn off the conduction.

When the load (3) is a 30A linear load [2 ovens and 1 hair dryer], please refer to the 26th figure 30A linear load starting current waveform without slow start. When the power supply starts, there is a surge The maximum current value is about 48A. Please refer to Figure 27. There is a slow start 30A linear load starting current waveform diagram. When the power supply starts, the maximum surge current is about 36A, so that through the slow start circuit ( 15) It can effectively reduce the surge current at startup by about 1.3 times. Please also refer to the 28th Figure 30A linear load current waveform diagram, the yellow waveform is the current waveform, the blue waveform is the output waveform of the current transformer through the amplification circuit, and the yellow waveform is set to 20A. When it is running stably The maximum current is about 48A, the blue waveform is set to 1V, with 2.5V as the center point, and the maximum current is about 1.6V when it is running stably. Please also refer to the 29th Figure 30A linear load overload protection test waveform diagram, the yellow waveform is the current waveform, and the blue waveform is the SCR drive signal. It can be known that the current will rise to more than 60A during a short circuit, and the SCR drive The signal will be turned off at the moment of short circuit, but the characteristics of SCR will turn off the conduction when the AC current crosses zero. This test is about 2.5ms to turn off the conduction.

When the load (3) is a 40A linear load [2 ovens, a hair dryer and a 1100W light bulb], please refer to Figure 30, as shown in the starting current waveform diagram of a 40A linear load without slow start, when the power is turned on The maximum inrush current is about 130A. Please refer to Figure 31. There is a slow start 40A linear load start current waveform diagram. When the power supply is started, the maximum inrush current is about 40A. The circuit (15) can effectively reduce the surge current at startup by about 3.25 times. Please also refer to the 32nd Figure 40A linear load current waveform diagram, the yellow waveform is the current waveform, the blue waveform is the output waveform of the current transformer through the amplification circuit, and the yellow waveform is set to 20A. When it is running stably The maximum current is about 60A, the blue waveform is set to a grid of 1V, with 2.5V as the center point, and the maximum current is about 2V when it is running stably. Please also refer to the 33rd Figure 40A linear load overload protection test waveform diagram, the yellow waveform is the current waveform, and the blue waveform is the SCR drive signal. It can be known that the current will rise above 60A when the short circuit occurs, and the SCR drive The signal will be turned off at the moment of short circuit, but the characteristics of SCR will turn off the conduction when the AC current crosses zero. This test is about 7.5ms to turn off the conduction.

Please also refer to the schematic diagram of the three-phase load test platform structure of the present invention shown in Figure 34, which makes each phase of power supply first pass through the 50A fuse and then connect to the electronic circuit breaker (1), and after the power supply to Three-phase AC motor, then let its two-phase power supply be set short-circuit switch to simulate the short-circuit of the equipment, and verify several important parameters of the electronic circuit breaker (1): slow start effect, response time and SCR under different loads. heat.

When the load (3) is a three-phase induction motor, please also refer to the starting current waveform diagram of the three-phase induction motor without slow start in Figure 35. When the power is started, the maximum surge current is about 20A. Please also refer to Figure 36 which shows the starting current waveform diagram of the slow-start three-phase induction motor. The inrush current at startup is about 4 times. Please also refer to the three-phase induction motor overload protection test waveform diagram in Figure 37. The yellow waveform is the current waveform, and the blue waveform is the SCR drive signal. It can be known that the current will rise to more than 25A during a short circuit. The driving signal will be turned off at the moment of short circuit, but the characteristics of SCR will turn off the conduction when the AC current crosses zero. This test is about 5ms to turn off the conduction.

In addition, the temperature rise of the dual SCR circuit (14) is verified by the current as follows. The temperature of the dual SCR circuit (14) will affect the conduction current. In order to avoid temperature damage to the dual SCR circuit (14), use the following experiment to verify the state of the fan What is the difference between the temperature rise and the state without a fan? The test method is to run stably for 60 minutes to check the relationship between different currents and temperature rise: please refer to the relationship between the current and SCR temperature in Figure 38. At 10A, the operating temperature goes from 23.2°C to 39.0°C in 21 minutes without a cooling fan, and with a cooling fan, it quickly reaches 26.6°C in 7 minutes; please refer to the third Figure 19 shows the relationship between 20A current and SCR temperature. In the case of 20A current, the operating temperature without cooling fan reaches 49.0°C from 22.4°C in 23 minutes, while using the cooling fan, it is limited to 34.0 from 8 minutes. °C; please also refer to Figure 40. The relationship between 30A current and SCR temperature is shown in Figure 40. In the case of 30A current, the operating temperature without cooling fan reaches 66.0°C from 21.1°C in 25 minutes, while using cooling fan The fan is limited to 39.5°C after 11 minutes; please refer to Figure 41. The relationship between 40A current and SCR temperature is shown in Figure 41. In the case of 40A current, the operating temperature without cooling fan is at 35 From 22.3°C to over 90.0°C within 1 minute, and using a cooling fan, the temperature remained at 51.0°C after 13 minutes; and from Table 1 below, it can be seen that the greater the current, the higher the temperature of the dual SCR circuit (14) The rise is higher, but it will not exceed the rated temperature regardless of whether there is a fan for cooling. electric current 10A 20A 30A 40A Stable temperature without fan cooling (°C) 40 52 68 95 The temperature when there is a stable cooling fan (°C) 28 35 40 52 Table 1 Temperature rise table

In addition, comparing the electronic circuit breaker (1) with the existing overload protection device according to: rated current, structure complexity, overall cost and response time, the current fuse and traditional circuit breaker technology on the market are very mature, and the rated current is also Larger, but the response time is relatively slow. Although the existing electronic circuit breaker has a response speed of less than 10 ms, it lacks a slow start circuit and can only use linear loads. The circuit proposed by the electronic circuit breaker (1) of the present invention is superior In the above products or traditional solutions, the response time is less than 10 ms, which is enough to protect electrical equipment from overload or short circuit hazards, and there is a slow start circuit to suppress the surge current during startup. Please refer to the comparison in Table 2 below. Electronic circuit breakers (1) can withstand rated currents up to 40 A. project fuse traditional circuit breaker electronic circuit breaker this invention slow start none none none have rated current ＞20A ＞20A <5A ＞40A architecture Simple complex ordinary ordinary cost Low middle middle middle Reaction time 50ms 100ms <10 ms <10 ms Table 2 Comparison Table of Overload Protection Devices

By the above, the description of the present invention's use and implementation shows that, compared with the prior art means, the present invention mainly has the following advantages:

1. The surge current at startup of the present invention is forced to pass through the slow-start circuit, and the NTC resistance of the slow-start circuit absorbs the generation of surge current, so it can be limited within the normal operating range, and its maximum surge current can be from 125A Effective suppression to below 40A.

2. The present invention can quickly disconnect the electrical equipment from the mains in less than 10 ms or even shorter response time in case of overload or short circuit, so as to protect the electrical equipment or avoid the influence of the regional power grid.

3. During the use of the present invention, the dual SCR circuit with a fan radiator is used, so that its working temperature is well controlled and has excellent stability.

4. The present invention can be applied to single-phase or three-phase power systems in actual industrial environments, making its application scope wider, and its overall implementation and use have more practical features.

However, the above-mentioned embodiments or drawings do not limit the product structure or usage of the present invention, and any appropriate changes or modifications by those with ordinary knowledge in the technical field shall be considered as not departing from the patent scope of the present invention.

To sum up, the embodiment of the present invention can indeed achieve the expected use effect, and the specific structure disclosed by it has not only never been seen in similar products, nor has it been disclosed before the application, and it has fully complied with the provisions of the Patent Law In accordance with the requirements, it is very convenient to file an application for a patent for invention in accordance with the law, and sincerely ask for the review and approval of the patent.

1: Electronic circuit breaker

11: Current transformer

12: Amplifier

13: Secondary controller

14: Double SCR circuit

15: Slow start circuit

16: Main controller

2: Power terminal

3: load

Figure 1: Schematic diagram of the structure of the present invention

Figure 2: Schematic diagram of another embodiment of the present invention [three-phase power supply]

The third figure: 2.5V high-precision reference voltage circuit diagram of the present invention

Figure 4: Amplifier circuit diagram of the present invention

Figure 5: The current overload detection circuit diagram of the present invention

Figure 6: The slow start circuit diagram of the present invention

The seventh figure: TRIAC driving circuit diagram of the present invention

Figure 8: TRAIC current and SCR current measurement diagram of the present invention

Figure 9: Schematic diagram of the double SCR circuit of the present invention

Figure 10: Schematic diagram of the test platform architecture of the present invention

Figure 11: Starting current waveform diagram of 3/4 hp single-phase AC motor without slow start

Figure 12: Starting current waveform of a 3/4 hp single-phase AC motor with slow start

Figure 13: 3/4 single-phase AC motor current waveform

Figure 14: Starting Current Waveform Diagram of 1100W Bulb Without Slow Start

Figure 15: Starting current waveform of 1100W light bulb with slow start

Figure 16: 1100W bulb current waveform

Figure 17: 1100W bulb overload protection test waveform

Figure 18: Starting current waveform diagram of 10A linear load without slow start

Figure 19: Starting current waveform of 10A linear load with slow start

Figure 20: 10A linear load current waveform

Figure 21: 10A linear load overload protection test waveform

Figure 22: 20A linear load starting current waveform without slow start

Figure 23: Starting current waveform of 20A linear load with slow start

Figure 24: 20A linear load current waveform

Figure 25: 20A linear load overload protection test waveform

Figure 26: Starting current waveform diagram of 30A linear load without slow start

Figure 27: Starting current waveform of 30A linear load with slow start

Figure 28: 30A linear load current waveform

Figure 29: 30A linear load overload protection test waveform

Figure 30: Starting current waveform diagram of 40A linear load without slow start

Figure 31: Starting current waveform of 40A linear load with slow start

Figure 32: 40A linear load current waveform

Figure 33: 40A linear load overload protection test waveform

Figure 34: Schematic diagram of the structure of the three-phase load test platform of the present invention

Figure 35: Starting current waveform of a three-phase induction motor without slow start

Figure 36: Starting current waveform of a three-phase induction motor with slow start

Figure 37: Three-phase induction motor overload protection test waveform

Figure 38: Relationship between 10A current and SCR temperature

Figure 39: Relationship between 20A current and SCR temperature

Figure 40: Relationship between 30A current and SCR temperature

Figure 41: Relationship between 40A current and SCR temperature

1: Electronic circuit breaker

11: Current transformer

12: Amplifier

13: Secondary controller

14: Double SCR circuit

15: Slow start circuit

16: Main controller

2: Power terminal

3: load

Claims (2)

A high-speed electronic circuit breaker with dual-path switching, which mainly includes an electronic circuit breaker; wherein: In the electronic circuit breaker, the current transformer is connected to the power supply terminal, and an amplifier is connected to the output terminal of the current transformer. The output terminal of the amplifier is connected to a sub-controller, and the sub-controller has built-in current overload detection circuit, so that the output signal of the current transformer is amplified by the amplifier and then transmitted to the sub-controller, and the current overload detection circuit built in the sub-controller is used to detect whether the current is overloaded, and at the output terminal of the current transformer Also connected with dual SCR circuit and slow start circuit respectively, the dual SCR circuit is two Silicon Controlled Rectifiers [Silicon Controlled Rectifier, SCR] connected in reverse parallel, and the output terminal of the secondary controller is respectively connected with the dual SCR circuit , The slow start circuit is connected to the main controller, the slow start circuit is responsible for absorbing the surge current generated during startup, so that the output terminal of the main controller is connected to the secondary controller, and the dual SCR circuit and the slow start The circuit is connected to the load, and the load is also connected to the power supply terminal, so that after the slow start is over, the secondary controller triggers the conduction of the dual SCR circuit, and realizes the full-wave conduction function through the dual SCR circuit. The high-speed electronic circuit breaker with dual-path switching as described in claim 1, wherein, when the electronic circuit breaker is applied to the three-phase power supply terminals, the three-phase power supply terminals are respectively connected to three groups of the electronic circuit breakers The current transformer, and the output terminals of the sub-controllers of the three sets of electronic circuit breakers are all connected to the same main controller, and the output terminals of the main controller are respectively connected to the three sets of electronic circuit breakers The sub-controller of the device.

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