Solid state circuit interrupter

Abstract

A circuit interrupter includes a solid state switch and a mode control circuit. The solid state switch is connected in series between a line input and a load output of the circuit interrupter. The mode control circuit is configured to execute a first control mode and a second control mode to control operation of the circuit interrupter. The first control mode is configured to generate a self-bias turn-on threshold voltage for the solid state switch during power-up of the circuit interrupter while maintaining the solid state switch in an off state until the self-bias turn-on threshold voltage is generated. The second control mode is configured to interrupt the self-bias turn-on threshold voltage and place the solid state switch in an off state.

Description

[0001] Cross-references to related applications

[0002] This application is a partial continuation-in-process of U.S. Patent Application Serial No. 16 / 149,094, filed October 1, 2018, the disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to power control systems and apparatus, and in particular to solid-state circuit interrupter apparatus and systems for interrupting power loads under fault or hazardous conditions. Background Technology

[0004] Circuit breakers are an important component of power distribution systems, typically located between high-current public supply circuits and low-current branch circuits within a given building or residential structure. They protect branch circuit conductors and electrical loads from overcurrent conditions. There are several types of overcurrent conditions, including overload conditions and fault conditions. An overload condition is defined as equipment operating beyond its normal full-load rating, or a branch exceeding its current-carrying capacity, which, if sustained for a sufficient period, will lead to damage or dangerous overheating. Fault conditions include unplanned or unexpected load conditions, which typically generate much higher overcurrent conditions than overload conditions, depending on the fault impedance. The fault that produces the maximum overcurrent condition is called a short circuit or "bolt fault."

[0005] Conventional circuit breakers are essentially electromechanical and have electrical contacts that physically separate via manual intervention of an operating lever or automatically upon the occurrence of a fault condition or prolonged overcurrent. In these cases, the circuit breaker is considered to have "tripped." The electrical contacts of a circuit breaker can separate electromagnetically, mechanically, or a combination of both.

[0006] A serious problem with conventional circuit breakers is their slow response to fault conditions due to their electromechanical construction. Conventional circuit breakers typically require at least several milliseconds to isolate fault conditions. This slow response time is undesirable because it increases the risk of dangerous fires, damage to electrical equipment, and arc flashes, which can occur at short-circuit locations if bolt faults are not isolated quickly enough. An arc flash is an electrical explosion of a conductor that creates a short-circuit condition. The energy release of an arc flash can generate temperatures exceeding 35,000°F at the terminal, causing rapid vaporization of metallic conductors, molten metal explosions, and the expansion of plasma ejected outward with extreme force. Therefore, arc flashes are extremely dangerous to life, property, and electrical equipment, especially in industrial and residential applications where the risk of gas leaks is high.

[0007] Besides being slower at isolating faults, conventional circuit breakers also exhibit significant variations in tripping time and current tripping limits when responding to faults or prolonged overcurrent conditions. These variations are primarily due to limitations in the electromechanical design of the circuit breaker unit, as well as the influence of physical factors such as installation stress and temperature variations. The variations in tripping time and current tripping limits can themselves differ between units, even if they are of the same type, have the same ratings, and belong to the same manufacturer.

[0008] Conventional circuit breakers provide strong isolation once they trip. However, their slow response time, lack of accuracy, and high variability are all highly undesirable characteristics. Not only does the slow response time result in insufficient protection against potential arc flashes, but the high variability and lack of accuracy make it nearly impossible to coordinate multiple circuit breakers in a complex system.

[0009] As a protective device, even if the fault current greatly exceeds the circuit breaker's trip current rating, the circuit breaker must be able to isolate the fault from the public supply circuit, thus preventing the fault from becoming an internal single point of failure. The ampere breaking capacity (AIC) rating of a circuit breaker indicates the maximum fault current (in amperes) that the circuit breaker can safely clear when a fault occurs on the load side of the circuit breaker device. The AIC rating of a circuit breaker device refers to the maximum fault current that the circuit breaker device can interrupt without a fault occurring. AIC ratings require very high short-circuit protection levels, and the AIC rating of household circuit breakers is typically above 10,000 amperes. Summary of the Invention

[0010] Embodiments of this disclosure include solid-state circuit interrupter devices and systems for interrupting power from a power source to a load. For example, in one embodiment, the circuit interrupter includes a solid-state switch and mode control circuitry. The solid-state switch is connected in series between a line input and a load output of the circuit interrupter and is configured to be in one of (i) an ON state and (ii) an OFF state, wherein being in the ON state provides an electrical connection in an electrical path between the line input and the load output. The mode control circuitry is configured to execute a first control mode and a second control mode to control the operation of the circuit interrupter. The first control mode is configured to generate a self-biased ON threshold voltage for the solid-state switch during power-on of the circuit interrupter, while maintaining the solid-state switch in the OFF state until the self-biased ON threshold voltage is generated. The second control mode is configured to interrupt the self-biased ON threshold voltage and place the solid-state switch in the OFF state.

[0011] In another embodiment, the circuit breaker includes a solid-state switch, an air-gap electromagnetic switch, a switch controller, a zero-crossing sensor, and a current sensor. The solid-state switch and the air-gap electromagnetic switch are connected in series between the line input and the load output of the circuit breaker. The switch controller is configured to control the operation of the solid-state switch and the air-gap electromagnetic switch. The zero-crossing sensor is configured to detect the zero-crossing point of a power supply waveform input to the line input of the circuit breaker. The current sensor is configured to sense the current flowing in the electrical path between the line input and the load output and to detect a fault condition. In response to the detection of a fault condition by the current sensor, the switch controller is configured to generate a switch control signal to (i) place the solid-state switch in a closed state and (ii) place the air-gap electromagnetic switch in an open state after the solid-state switch is placed in the closed state. The switch controller uses the zero-crossing detection signal output by the zero-crossing sensor to detect a zero-crossing event of the power supply waveform and places the air-gap electromagnetic switch in the open state in response to the detected zero-crossing event.

[0012] Other embodiments will be described in the following detailed description of the embodiments, which should be read in conjunction with the accompanying drawings. Attached Figure Description

[0013] Figure 1A A typical embodiment of a circuit interrupter is illustrated schematically.

[0014] Figure 1B Another conventional embodiment of a circuit interrupter is illustrated schematically.

[0015] Figure 1C Another conventional embodiment of a circuit interrupter is illustrated schematically.

[0016] Figure 2 A solid-state circuit interrupter according to one embodiment of the present disclosure is illustrated schematically.

[0017] Figure 3 A solid-state circuit interrupter according to another embodiment of the present disclosure is illustrated schematically.

[0018] Figure 4 A solid-state circuit interrupter according to another embodiment of the present disclosure is illustrated schematically.

[0019] Figure 5 A solid-state circuit interrupter according to another embodiment of the present disclosure is illustrated schematically.

[0020] Figure 6 A solid-state circuit interrupter according to another embodiment of the present disclosure is illustrated schematically.

[0021] Figure 7 A solid-state circuit interrupter according to another embodiment of the present disclosure is illustrated schematically.

[0022] Figure 8 A solid-state circuit interrupter according to another embodiment of the present disclosure is illustrated schematically.

[0023] Figure 9A Instructions for input Figure 8 The power supply voltage waveform on the line side of the solid-state circuit interrupter.

[0024] Figure 9B This explains when Figure 8 The output voltage waveform on the load side of the solid-state circuit interrupter when the solid-state switch of the circuit interrupter is in the off state and the air gap electromagnetic switch of the circuit interrupter is in the closed state.

[0025] Figure 10 According to one embodiment of this disclosure, by Figure 8 A flowchart illustrating the switching control process implemented by the switching controller of a solid-state circuit interrupter.

[0026] Figure 11A According to one embodiment of this disclosure, it is possible to Figure 8 A schematic block diagram of an AC-DC converter circuit implemented in a solid-state circuit interrupter.

[0027] Figure 11B According to one embodiment of this disclosure, Figure 11A A schematic circuit diagram of an AC-DC converter. Detailed Implementation

[0028] The embodiments disclosed herein will further describe in detail solid-state circuit interrupter devices and systems for detecting and interrupting power from a power source to a load based on fault conditions (such as short-circuit faults, overcurrent faults, ground faults, arc faults, etc.) and hazardous environmental conditions (such as floods, chemical leaks, gas leaks, etc.). It should be understood that the same or similar reference numerals are used in all figures to denote the same or similar features, elements, or structures; therefore, detailed descriptions of the same or similar features, elements, or structures will not be repeated in every figure. Furthermore, the terms “about” or “substantially” used herein with respect to percentages, ranges, etc., mean close to or approximately, but not precisely. For example, the terms “about” or “substantially” as used herein mean that there is a small margin of error, such as 1% or less less than the specified amount. The term “exemplary” as used herein means “as an example, instance, or illustration.” Any embodiment or design described herein as “exemplary” is not to be construed as preferentially superior to other embodiments or designs.

[0029] Figure 1AA conventional embodiment of a circuit interrupter is illustrated schematically. Specifically, Figure 1A A circuit interrupter 100 is described, which is connected between a common power supply 10 (here referring to AC power supply 10) and a load 20, which is connected to a branch protected by the circuit interrupter 100. Further as... Figure 1A As shown, the circuit interrupter 100 is connected between the hot phase 11 ("line hot") of the AC power supply 10 and the load hot line 21 of the load 20, while the neutral phase 12 ("line neutral") of the AC power supply 10 is directly connected to the load neutral line 22 of the load 20. Further as... Figure 1A As shown, the line neutral 12 is connected to ground 14 (GND), thereby providing additional protection known in the art.

[0030] The circuit interrupter 100 includes an AC switch 105 and a controller 110. The AC switch 105 includes a TRIAC or a silicon controlled rectifier (SCR). The TRIAC switch 105 is a three-terminal electronic device that conducts current bidirectionally under the control of the controller 110. TRIACs are commonly found in conventional wall-mounted dimmer switches. The controller 110 represents many possible control embodiments, whether it is a logic gate, microcontroller, or electromechanical control, such as the bimetallic bent strip used in conventional circuit breakers. The controller 110 can apply control signals to the gate (G) of the TRIAC switch 105 to modulate the phase angle and turn the TRIAC switch 105 on and off. The phase angle control of the TRIAC switch 105 can control the average current flowing into the load 20 and is commonly used to control motor speed, dim lights, or control electric heaters, etc.

[0031] Figure 1B Another conventional embodiment of the circuit interrupter 101 is illustrated schematically. The circuit interrupter 101 includes a controller 110 and an AC switch, the AC switch including, for example... Figure 1B The diagram shows a first diode 125, a second diode 130, a first transistor 135, and a second transistor 140 interconnected. The first transistor 135 and the second transistor 140 comprise insulated-gate bipolar transistor (IGBT) devices. The controller 110 controls the current by simultaneously injecting control signals into the first transistor 135 and the second transistor 140. The AC switch is configured as follows... Figure 1B As shown, during the positive half-cycle of the power supply voltage waveform of the AC power supply 10, the current flows only through the first switch 135 and the second diode 130, while during the negative half-cycle of the power supply voltage waveform of the AC power supply 10, the current flows only through the second switch 140 and the first diode 125.

[0032] Figure 1B One drawback of the circuit interrupter 101 shown is that it requires the implementation of four discrete components (such as diodes 125 and 130 and BJT devices 135 and 140). Furthermore, the BJT devices 135 and 140 cannot operate efficiently as bidirectional switches, and the discrete diodes 125 and 130 must be used for bidirectional switching. Additionally, the forward bias voltage drop of the discrete diodes 125 and 130 is relatively large (approximately 0.7V) compared to the forward bias voltage drop of the BJT devices 135 and 140 (approximately 0.1V-0.2V). Therefore, the diodes 125 and 130 increase the power loss of the circuit interrupter 101.

[0033] Figure 1C Another conventional embodiment of the circuit interrupter 103 is illustrated schematically. The circuit interrupter 103 is similar to... Figure 1B The circuit interrupter 101, because the circuit interrupter 103 includes a first controller 110 and a first AC switch, the first AC switch including a first diode 125, a second diode 130, a first transistor 135 and a second transistor 140, the first diode, the second diode, the first transistor and the second transistor as... Figure 1C The circuit interrupter 103 is interconnected to provide a bidirectional switch in the electrical path between the line heat 11 and the load heat 21. The circuit interrupter 103 further includes a second controller 111 and a second AC switch, the second AC switch including a first diode 145, a second diode 150, a first transistor 165, and a second transistor 170, wherein the first diode, the second diode, the first transistor, and the second transistor are as follows: Figure 1C The interconnections shown provide a bidirectional switch in the electrical path between line neutral 12 and load neutral 22. The transistors 135, 140, 165, and 170 are insulated-gate bipolar transistors.

[0034] The first controller 110 controls the current by simultaneously applying control signals to switches 135 and 140, while the second controller 111 controls the current by simultaneously applying control signals to switches 165 and 170. During the positive half-cycle of the AC power supply voltage waveform of the AC power source 10, current (i) flows through the switch 135 and the diode 130 in the hot line path and (ii) flows through the switch 170 and the diode 145 in the neutral line path. On the other hand, during the negative half-cycle of the AC power supply voltage waveform of the AC power source 10, current (i) flows through the switch 140 and the diode 125 in the hot line path and (ii) flows through the switch 165 and the diode 150 in the neutral line path. This configuration of simultaneously controlling the AC switches on the line and neutral is called bipolar switching and can be applied to two lines from different phases of a single AC energy source. Bipolar switching of the line and neutral is a commonly used AC switching technique in ground fault circuit interrupter (GFCI) rescue applications. The circuit interrupter 103 has similar disadvantages to the circuit interrupter 102 discussed above, but the disadvantages are amplified because the circuit interrupter includes four additional discrete components with additional diodes 145 and 150 that increase power loss.

[0035] like Figure 2 , 3 The exemplary embodiments of this disclosure shown in Figures 4, 5, 6, 7, and 8 include a novel architecture for a circuit interrupter device and system, which may be located between an input power source and an output load. While the exemplary circuit interrupter is generally described as connecting an AC power source 10 and a load 20, it should be understood that the exemplary circuit interrupter can be embodied in various devices and applications. For example, in some embodiments, such as... Figure 2-8 The circuit interrupter shown can be implemented in a circuit breaker device (such as a smart circuit breaker device) located in the circuit breaker distribution board. Furthermore, in some embodiments, such as... Figure 2-8 The circuit interrupter shown can be implemented in an electrical outlet device or a light switch (such as a wall-mounted light switch, or a light switch installed in a smart luminaire or smart ceiling bulb holder). In other embodiments, such as Figure 2-8 The circuit interrupter shown may include a stand-alone device that may be located in a junction box in the electrical network of a residence or building and configured to protect one or more electrical devices, appliances, loads, etc. connected downstream of the stand-alone circuit interrupter device.

[0036] Figure 2 A solid-state circuit interrupter according to an embodiment of the present disclosure is illustrated schematically. Specifically, Figure 2A solid-state circuit interrupter 200 connected between AC power supply 10 and load 20 is schematically illustrated. The solid-state circuit interrupter 200 includes a double-pole single-throw (DPST) switching circuit 202, which includes a first solid-state switch 210, a second solid-state switch 212, a first mode control circuit 220, a second mode control circuit 222, a first current sensor 230, and a second current sensor 232. The solid-state circuit interrupter 200 also includes a first bias branch circuit and a second bias branch circuit. The first bias branch circuit includes a first diode 240 and a first resistor 250, and the second bias branch circuit includes a second diode 242 and a second resistor 252. The first diode 240 and the first resistor 250 are connected in series between the line neutral 12 and the first mode control circuit 220. The second diode 242 and the second resistor 252 are connected in series between the line neutral 11 and the second mode control circuit 222.

[0037] exist Figure 2 In an exemplary embodiment, the first and second solid-state switching elements 210 and 212 include power MOSFET (metal-oxide-semiconductor field-effect transistor) devices, particularly N-type enhancement MOSFET devices having a gate terminal (G), a drain terminal (D), and a source terminal (S), as shown in the figure. Figure 2 In exemplary embodiments (and other embodiments discussed herein), the first and second solid-state switches 210 and 212 include inherent body diodes 210-2 and 212-1, the body diodes representing the PN junction between the P-type substrate body and the N-doped drain region of the MOSFET device. Therefore, the body diodes 210-1 and 212-1 are inherent elements (i.e., not discrete elements) of the MOSFET switches 210 and 212. It should be noted that the inherent body-source diodes of the solid-state switches 210 and 212 are not shown as if they were short-circuited between the source region and the substrate body (e.g., the N+ source and P body junction are short-circuited through source metallization).

[0038] The first and second mode control circuits 220 and 222 are configured to implement multiple control modes for the solid-state interruptor 200, including (i) a self-biased turn-on threshold voltage control mode and (ii) a forced turn-off control mode. In some embodiments, the self-biased turn-on threshold voltage control mode utilizes a self-biasing circuit to generate a target turn-on threshold voltage level for the solid-state switches 210 and 212, while preventing the solid-state switches 210 and 212 from turning on until the target self-biased turn-on threshold voltage level is reached and applied to the solid-state switches 210 and 212 to turn them on.

[0039] As further explained below, the self-biasing network is configured to delay the application of the gate voltage to the gate terminals of the solid-state switches 210 and 212, with a delay long enough to prevent the switches 210 and 212 from being prematurely "turned on" before the self-biased turn-on threshold voltage level is generated. In fact, prematurely turning on the solid-state switches 210 and 212 will prevent the generated self-biased turn-on threshold voltage from reaching the target voltage level. The self-biased turn-on threshold voltage control mode is supported by first and second bias branch circuits with an opposite cyclic arrangement, the first and second bias branch circuits consisting of diodes 240 and 242 and resistors 250 and 252.

[0040] In some embodiments, the forced shutdown control mode of the first and second mode control circuits 220 and 222 is configured to forcibly shut down solid-state switches 210 and 212 in response to the detection of certain events, including but not limited to fault event detection, hazardous environmental condition detection, circuit interruption remote commands, etc. Further detailed below, the forced shutdown control mode can be activated by commands, such as through direct hardware fault sensing and control and / or through electrical insulation control inputs based on (but not limited to) optical, magnetic, capacitive, and RF insulation technologies.

[0041] In some embodiments, the first and second current sensors 230 and 232 are configured to sense the magnitude of current flowing to and from the load 20 and generate current sensing data, which the first and second mode control circuits 220 and 222 can use to identify fault events (such as short-circuit fault events, overcurrent fault events, arcing fault events, etc.). In response to the detection of such fault events, the first and second current sensors 230 and 232 are configured to trigger a forced shutdown mode, which causes the first and second solid-state switches 210 and 212 to shut down. The first and second current sensors 230 and 232 can be implemented using various types of sensing techniques and circuits, including, but not limited to, sensing techniques based on the sensing resistance, current transformer, Hall effect sensor, or internal impedance (drain-source resistance) of the solid-state switches 210 and 212. The mode control circuits 220 and 222 can be implemented using various types of control architectures based on logic gates, microcontrollers, electromechanical control devices, etc.

[0042] During normal operation of the solid-state interruptor 200, during the positive half-cycle of the power supply voltage waveform of the AC power supply 10, the first mode control circuit 230 applies a generated self-biased turn-on threshold voltage to the gate terminal of the first solid-state switch 210 to turn on the first solid-state switch 210. In this configuration, positive current flows from the line heat 11 through the first solid-state switch 210 to the load 20, and the current returns to the line neutral 12 through the positive bias inherent diode 212-1 of the second solid-state switch 212. On the other hand, during the negative half-cycle of the power supply voltage waveform of the AC power supply 10, the second mode control circuit 222 applies a generated self-biased turn-on threshold voltage to the gate terminal of the second solid-state switch 212 to turn on the second solid-state switch 212. In this configuration, negative current flows from the line neutral 12 through the second solid-state switch 212 to the load 20, and the current returns to the line heat 11 through the positive bias inherent diode 210-1 of the first solid-state switch 210.

[0043] Figure 3 A solid-state circuit interrupter according to another embodiment of the present disclosure is illustrated schematically. Specifically, Figure 3 This schematically illustrates the basis Figure 2 The solid-state circuit interrupter 300 of the frame is described, but exemplary embodiments of the first and second mode control circuits 220 and 222 are further illustrated. Figure 3 As shown, the first mode control circuit 220 includes a capacitor 310, a Zener diode 320, a resistor 330, an operational amplifier 350 (configured as a comparator), control switches 360 and 370, and a sensor 380. Similarly, the second mode control circuit 222 includes a capacitor 312, a Zener diode 322, a resistor 332, an operational amplifier 352 (configured as a comparator), control switches 362 and 372, and a sensor 380. The mode control circuits provide exemplary embodiments for implementing (i) a self-biased turn-on threshold voltage control mode using circuit components 310 / 312, 320 / 322, 330 / 332, 350 / 352, and 360 / 362, and (ii) a forced-off control mode using circuit components 340 / 342, 370 / 372, and sensor 380.

[0044] For example, in the self-biased turn-on threshold voltage control mode, comparators 350 and 352 will output a control voltage sufficient to activate control switches 360 and 362 and effectively short-circuit the gate-source of the first and second solid-state switches 210 and 212. The solid-state switches 210 and 212 remain in the off state for a sufficiently long time to generate the self-biased turn-on threshold voltage for the solid-state switches 210 and 212.

[0045] For example, during the positive half-cycle of the AC power supply voltage waveform of AC power supply 10, current flows from line heat 11 through the second branch circuit (including the diode 242 and the resistor 252), the capacitor 312, and the body diode 212-1 to the line neutral 12. This current causes the voltage across capacitor 312 to increase until the capacitor voltage reaches the target self-biased turn-on threshold voltage level on capacitor 312, which represents the clamping voltage (i.e., the reverse breakdown voltage of the Zener diode 322, referred to as the Zener voltage). In other words, the Zener voltage of the Zener diode 322 limits the self-biased turn-on threshold voltage (V) generated to turn on the second solid-state switch 212. GS (the maximum level)

[0046] Next, during the negative half-cycle of the AC power supply voltage waveform of AC power supply 10, current flows from line neutral 12 through the first branch circuit (including the diode 240 and the resistor 250), the capacitor 310, and the body diode 210-1 to the line heat 11. This current causes the voltage across capacitor 310 to increase until the capacitor voltage reaches the target turn-on threshold voltage level on capacitor 310, which represents the clamping voltage (Zener voltage) of Zener diode 320. In other words, the Zener voltage of Zener diode 320 limits the self-biased turn-on threshold voltage (V0) generated to turn on the first solid-state switch 210. GS (the maximum level)

[0047] In this exemplary embodiment, the target threshold voltage levels of the solid-state switches 210 and 212 are limited by the Zener voltages of the Zener diodes 320 and 322, thereby acting as solid-state clamps to limit the turn-on threshold voltage. Therefore, the self-biased turn-on threshold voltage control mode is independent of the input line voltage because the self-biased turn-on threshold voltage level is limited by the solid-state clamps.

[0048] As mentioned above, in Figure 3In the exemplary mode control framework, solid-state switches 210 and 212 remain in the off state for a sufficient period of time to charge capacitors 310 and 312 to the Zener voltage of Zener diodes 320 and 322. In some embodiments, the Zener voltage is approximately 15V, and the turn-on threshold voltage of solid-state switches 210 and 212 is in the range of approximately 10V to approximately 15V. If solid-state switches 210 and 212 turn on prematurely before reaching the clamping voltage of Zener diodes 320 and 322 due to leakage current, Miller capacitance of MOSFET devices, etc., the solid-state switches 210 and 212 can actually turn on at less than 2V of gate-source voltage, which would prevent capacitors 310 and 312 from charging sufficiently to generate a capacitor voltage corresponding to the clamping voltage of Zener diodes 320 and 322. Therefore, the self-biased turn-on threshold voltage control mode is configured to keep the control switches 360 and 362 on for a period of time sufficient to keep the first and second solid-state switches 210 and 212 off and allow the capacitors 310 and 312 to charge to the clamping voltage of the Zener diodes 320 and 322.

[0049] As described above, the mode control circuits 220 and 222 implement a forced shutdown control mode using the circuit components 340, 342, 370, 372, and 380. Specifically, during operation of the solid-state circuit interrupter 300, switches 370 and 372 can be activated by one of the sensors 380, effectively shunt the gate-source terminals and shut down the solid-state switches 210 and 212. Sensors 380 may comprise one or more sensors of various types. For example, in some embodiments, sensor 380 includes a current sensor configured to measure the voltage drop across sensing resistors 340 and 342 and determine the magnitude of the current flowing in the hot-line path and neutral-line path between the AC power supply 10 and the load 20 based on the measured voltage drop across the current sensing resistors 340 and 342. In some embodiments, the sensing resistors 340 and 342 have very small resistance values ​​(e.g., approximately 10 x less than 1 milliohm), and therefore, the voltage potentials of the sensing resistors 340 and 342 are negligible but sufficient for current sensing. The operational amplifiers 350 and 352 are configured with sufficient gain to drive their respective control switches 360 and 362, even with relatively small voltage inputs corresponding to the voltage drops of the sensing resistors 340 and 342.

[0050] In other embodiments, the sensor 380 includes one or more sensors configured to sense environmental conditions. For example, the sensor 380 may include one or more of the following: (i) a chemically sensitive detector configured to detect the presence of hazardous chemicals; (ii) a gas-sensitive detector configured to detect the presence of hazardous gases; (iii) a temperature sensor configured to detect high temperatures (indicating conditions such as fire); (iv) a piezoelectric detector configured to detect large vibrations (such as those associated with explosions, earthquakes, etc.); (v) a humidity sensor or water sensor configured to detect flood or humid conditions; and other types of sensors configured to detect the presence or occurrence of hazardous environmental conditions that could lead to circuit interruption.

[0051] In some embodiments, the control switches 370 and 372 include phototransistors (such as phototransistors) or other types of light-controlled switches that receive signals from complementary light-emitting diodes (LEDs) controlled by, for example, sensor devices or microcontrollers. This optical coupling between the sensor 380 and the control switches 370 and 372 essentially provides current isolation between the forced shutdown control circuitry and the switching circuitry of the solid-state circuit interrupter 300. In other embodiments, current isolation can be achieved using magnetic, capacitive, or radio frequency (RF) isolation techniques.

[0052] In other embodiments, the control switches 370 and 372 may be activated in response to a remote command (e.g., an alarm signal) received from a local or remote controller configured to detect faults, or from an individual that can control the operation of the solid-state circuit interrupter 300 via smart technology (implemented via, for example, an Internet of Things (IoT) wireless computing network, wherein the solid-state circuit interrupter 300 includes a smart wireless IoT device).

[0053] Figure 4 A solid-state circuit interrupter according to another embodiment of the present disclosure is illustrated schematically. Specifically, Figure 4A solid-state circuit interrupter 400 is described, connected between AC power supply 10 and load 20. The solid-state circuit interrupter 400 includes a unipolar switching circuit comprising a first solid-state switch 401 and an associated body diode 401-1, and a second solid-state switch 402 and an associated body diode 402-1. The first and second solid-state switches 401 and 402 are connected in series in an electrical path between line heat 11 and load heat 21, with the source terminal (S) connected in series via a sensing resistor 440, thereby achieving bidirectional solid-state switching. The solid-state circuit interrupter 400 also includes a first bias branch circuit and a second bias branch circuit, wherein the first bias branch circuit includes a first diode 240 and a first resistor 250, and the second bias branch circuit includes a second diode 242 and a second resistor 252. The first and second bias branch circuits are connected in series between line heat 11 and line neutral 12, as shown in the figure.

[0054] The solid-state interrupter 400 also includes a mode control circuit 405, which includes a first capacitor 410, a Zener diode 420, resistors 430, 440, 450 and 452, a second capacitor 454, a first control switch 460, a second control switch 470, and a sensor 480. The first and second bias branch circuits are connected to the input node N1 of the mode control circuit 405. Figure 4 The mode control circuit 405 shown includes features for implementing... Figure 2 Another exemplary embodiment of each of the mode control circuits 220 and 222. The mode control circuit 405 is configured to (i) implement a self-biased turn-on threshold voltage control mode using circuit components 410, 420, 430, 450, 452, 454 and 460 and (ii) implement a forced turn-off control mode using circuit components 440, 470 and 480.

[0055] For example, in the self-biased turn-on threshold voltage control mode, resistors 450 and 452, along with capacitor 454, will generate a voltage at node N2 sufficient to activate the first control switch 460 and effectively short-circuit the gate-source of the first and second solid-state switches 401 and 402. The voltage at node N2 will keep solid-state switches 401 and 402 in the off state for a delay corresponding to the RC time constant of resistors 452 and capacitor 454.

[0056] During this RC time constant delay, and during the negative half-cycle of the AC power supply voltage waveform of AC power supply 10, current flows from line neutral 12 through the first branch circuit (including the diode 240 and the resistor 250), the capacitor 410, and the body diode 401-1 to the line heat 11. This current causes the voltage across capacitor 410 to increase until the capacitor voltage reaches a target turn-on threshold voltage level on capacitor 410, which represents a clamping voltage (i.e., the Zener voltage of the Zener diode 420). In other words, the Zener voltage of the Zener diode 420 limits the self-biased turn-on threshold voltage (V0) generated to turn on the first and second solid-state switches 401 and 402. GS (the maximum level)

[0057] In this exemplary embodiment, the target threshold voltage level is limited by the Zener voltage (i.e., reverse breakdown voltage) of the Zener diode 420, thereby the Zener diode 420 acts as a solid-state clamp to limit the turn-on threshold voltage. Therefore, the self-biased turn-on threshold voltage control mode is independent of the input line voltage because the self-biased turn-on threshold voltage level is limited by the solid-state clamp. During the positive half-cycle of the AC power supply voltage waveform of the AC power supply 10, the diode 242, the resistor 252, and the capacitor 410 maintain the turn-on threshold voltage (i.e., the Zener voltage) for the first and second solid-state switches 401 and 402 through trickle charging of the Zener diode 420.

[0058] As mentioned above, in Figure 4 In the exemplary mode control framework, the solid-state switch 401 remains in the off state for a sufficiently long time to charge the capacitor 410 to the Zener voltage of the Zener diode 420. In some embodiments, the Zener voltage is approximately 15V, and the turn-on threshold voltages of the solid-state switches 401 and 402 are in the range of approximately 10V to approximately 15V. If the solid-state switch 401 turns on prematurely before reaching the clamping voltage of the Zener diode due to reasons such as leakage current, Miller capacitance of the MOSFET device, etc., the solid-state switch 401 can actually turn on at less than 2V of gate-source voltage, which would prevent the capacitor 410 from charging sufficiently to generate a capacitor voltage corresponding to the clamping voltage of the Zener diode 420. Therefore, the self-biased turn-on threshold voltage control mode is configured to keep the control switch 460 on for a period of time sufficient to keep the first and second solid-state switches 401 and 402 off and allow the capacitor 410 to charge to the clamping voltage of the Zener diode 420.

[0059] As described above, the mode control circuit 405 uses the circuit components 440, 470, and 480 to implement a forced shutdown control mode. Specifically, during operation of the solid-state circuit interrupter 400, switch 470 can be activated by one of the sensors 480, effectively shunting the gate-source terminals and shutting off the solid-state switches 401 and 402. Sensor 480 may comprise one or more sensors of various types. For example, in some embodiments, sensor 480 includes a current sensor configured to measure the voltage drop across sensing resistor 440 and determine the magnitude of the current in the thermal path between line heat 11 and load heat 21 based on the measured voltage drop across sensing resistor 440. In some embodiments, sensing resistor 440 has a resistance value of less than 1 milliohm. Therefore, the voltage potential of sensing resistor 440 is negligible but sufficient for current sensing. The potential difference between sensing resistor 440 and ground of the sensing circuit is small and is compensated for by the bidirectional current through sensing resistor 440.

[0060] In other embodiments, the sensor 480 includes one or more sensors configured to sense environmental conditions. For example, the sensor 480 may include (i) a chemically sensitive detector configured to detect the presence of hazardous chemicals, (ii) a gas-sensitive detector configured to detect the presence of hazardous gases, (iii) a temperature sensor configured to detect high temperatures (indicating conditions such as fire), (iv) a piezoelectric detector configured to detect large vibrations (such as those associated with explosions, earthquakes, etc.), (v) a humidity sensor or water sensor configured to detect flood or humid conditions, and one or more other types of sensors configured to detect the presence or occurrence of hazardous environmental conditions that could lead to circuit interruption.

[0061] In some embodiments, the switch 470 includes a phototransistor (such as a phototransistor) or other type of light-controlled switch that receives a signal from a complementary light-emitting diode (LED) controlled by a sensor device or microcontroller. This optical coupling between the sensor 480 and the switch 470 essentially provides current isolation between the forced shutdown control circuitry and the switching circuitry of the solid-state circuit interrupter 400. In other embodiments, current isolation can be achieved using magnetic, capacitive, or radio frequency (RF) isolation techniques.

[0062] In other embodiments, the switch 470 may be activated in response to a remote command (e.g., an alarm signal) received from a local or remote controller configured to detect faults, or from an individual that can control the operation of the solid-state circuit interrupter 400 via smart technology (implemented via, for example, an Internet of Things (IoT) wireless computing network, wherein the solid-state circuit interrupter 400 includes a smart wireless IoT device).

[0063] Figure 5 A solid-state circuit interrupter according to another embodiment of the present disclosure is illustrated schematically. Specifically, Figure 5 The solid-state circuit interrupter 500 is illustrated schematically, and the solid-state circuit interrupter is similar to... Figure 4 The solid-state circuit interrupter 400, in addition to including an insulating circuit 510 to provide current insulation between the solid-state circuit interrupter 400 and the load 20 when the solid-state switches 401 and 402 are off, can generate a small amount of leakage current when the solid-state switches 401 and 402 are off. For example, even when the solid-state switches 401 and 402 are biased to the fully off state, a small amount of leakage current (e.g., 200 μA) can still flow through the solid-state switches 401 and 402 and generate a considerable voltage drop across the load 20 when the load 20 includes a high-impedance load.

[0064] The insulation circuit 510 shuns unwanted leakage current flowing from the AC power supply 10 to the load 20 via closed solid-state switches 401 and 402. The insulation circuit 510 includes a controller 520, MOSFET devices 530 and 540, and associated body diodes 530-1 and 540-1. During the off state of the solid-state switches 401 and 402, the controller 520 commands the MOSFET switches 530 and 540 to turn on, thereby shunting the unwanted leakage and preventing the leakage current from flowing into the load 20. The effect of bypassing or shunting the leakage current from the load 20 is equivalent to current insulation technology achieved using an air gap between the AC power supply 10 and the load 20. In this configuration, the insulation circuit 510 acts as a dummy air gap.

[0065] Figure 6 A solid-state circuit interrupter according to another embodiment of the present disclosure is illustrated schematically. Specifically, Figure 6 The solid-state circuit interrupter 600 is illustrated schematically, and the solid-state circuit interrupter is similar to... Figure 2The solid-state circuit interrupter 200, except that the solid-state switches 210 and 212 of the DPST conversion circuit 202 are coupled to the line hot lines 11-1 and 11-2 of the two independent hot phases 10-1 and 10-2 of the AC power supply 10, respectively, wherein the hot phases 10-1 and 10-2 are 180 degrees out of phase. In this configuration, the first branch circuit including the diode 240 and the resistor 250 is connected in series between the line neutral 12 and the first mode control circuit 220, and the second branch circuit including the diode 242 and the resistor 252 is connected in series between the line neutral 12 and the second mode control circuit 222. The mode control circuits 220 and 222 can use the above combination. Figure 3 , 4 The circuit architecture and mode control techniques discussed in section 5 are used to achieve this.

[0066] Figure 7 A solid-state circuit interrupter according to another embodiment of the present disclosure is illustrated schematically. Specifically, Figure 7 The solid-state circuit interrupter 700 is illustrated schematically, and the solid-state circuit interrupter is similar to... Figure 2 The solid-state circuit interrupter 200, except that the solid-state circuit interrupter 700 omits [the following]. Figure 2 The current sensors 230 and 232 shown are further comprising, as... Figure 5 The exemplary embodiment illustrates the insulating circuit 510. The insulating circuit 510 shunts the leakage current generated by the solid-state switches 210 and 212 in their off state, thereby preventing the leakage current from flowing through the load 20. As described above, bypassing or shunting the leakage current from the load 20 has the effect of current insulation.

[0067] Although the externally displayed current sensors 230 and 232 are omitted in the solid-state circuit interrupter 700, fault detection sensors in one or both of the mode control circuits 710 and 712 can still utilize the internal drain-source resistance (R0) of the solid-state switches 210 and 212. DS -ON) to determine the amount of current in the line heat or line neutral leg, and then in response to the detection of fault conditions (such as short circuit or overcurrent fault), deactivate the switches 210 and 212, and activate the insulation circuit 510 to shunt leakage current from the load 20 while the solid-state switches 210 and 212 remain in the off state.

[0068] In some embodiments, the mode control circuits 710 and 712 may utilize an independently isolated AC-DC power supply with a floating voltage output to implement a self-biased turn-on threshold voltage mode, which serves as the turn-on threshold voltage to bias the solid-state switches 210 and 212. In other embodiments, a current-isolated device (such as a capacitive, RF, or optically insulating device) may be used to implement the self-biased turn-on threshold voltage mode.

[0069] Figure 8 A solid-state circuit interrupter according to another embodiment of the present disclosure is illustrated schematically. Specifically, Figure 8 A solid-state circuit interrupter 800 connected between an AC power supply 10 and a load 20 is schematically illustrated, wherein the solid-state circuit interrupter 800 comprises a unipolar hybrid solid-state and mechanical circuit interrupter architecture. The solid-state circuit interrupter 800 includes a solid-state switch 810 and an air-gap electromagnetic switch 820 connected in series in an electrical path between the line heat 11 of the AC power supply 10 and the load heat 21 of the load 20 (e.g., the air-gap electromagnetic switch 820 and the solid-state switch 810 are connected in series between the line input and the load output of the solid-state circuit interrupter 800). The solid-state circuit interrupter 800 also includes an AC-DC converter circuit 830, a zero-crossing sensor 840, a current sensor 850, other types of sensors 860 (such as environmental sensors, light sensors, etc.), and a switch controller 870.

[0070] In such Figure 8 In some embodiments shown, the solid-state switch 810 includes a power MOSFET switch 810 (e.g., an N-type enhancement MOSFET device) having a gate terminal (G), a drain terminal (D), and a source terminal (S) as shown, and an intrinsic body diode 810-1. The air-gap electromagnetic switch 820 includes any suitable type of electromagnetic switching mechanism configured to physically open and close a set of electrical contacts, wherein an air gap is formed between the electrical contacts when the air-gap electromagnetic switch 820 is in the open state. For example, the air-gap electromagnetic switch 820 may include a latching electromagnet or relay element that responds to a control signal from the switch controller 870 to automatically open or close the electrical contacts of the air-gap electromagnetic switch 820.

[0071] An air gap is formed in the circuit path between the line heat source 11 and the load heat source 21, which can completely insulate the AC power supply 10 and the load 20, thus preventing current from flowing from the line heat source 11 to the load heat source 21. The air gap electromagnetic switch 820 can be disposed on the line side of the solid-state switch 810 (e.g., Figure 8(as shown) or on the load side of the solid-state switch 810. The solid-state circuit interrupter 800 provides a cost-effective solution that allows a solid-state switch to be used where electrical regulations require an air gap in the circuit interrupter for complete insulation (compared to several solid-state switches in the exemplary embodiments described above).

[0072] The AC-DC converter circuit 830 is configured to provide DC power to various circuits and components of the solid-state circuit interrupter 800, including the zero-crossing sensor 840, the switch controller 860, and optionally the current sensor 850 and other sensors 860 (depending on the configuration of these sensors 850 and 860). The AC-DC converter circuit 830 is configured to maintain power supply during faults when switches 810 and 820 are in the off and on states, respectively. In some embodiments, the AC-DC converter circuit 830 includes sufficient storage capacitance to immediately power the DC subsystem after a public power outage, so that when public power fails, the switch controller 870 can acquire and store relevant power interruption or short-circuit information and then wirelessly transmit it to a remote node, device, or system using a radio frequency transceiver (not shown) coupled to or integrated with the switch controller 870.

[0073] The zero-crossing sensor 840 is configured to monitor the voltage and / or current at a target point along the hot-line path of the solid-state circuit interrupter 800, and to detect zero-current and / or zero-voltage crossovers of the AC power supply voltage waveform of the AC power supply 10. For example, as Figure 8 As shown, the zero-crossing sensor 840 is coupled upstream of the hot-line path of switches 820 and 810 to detect zero-current and / or zero-voltage crossings of the AC power supply waveform of the AC power supply 10 at the line input of the solid-state circuit interrupter 800. The zero-crossing sensor 840 is coupled to the switch controller 870 via one or more data acquisition and control lines 840-1. The zero-crossing sensor 840 can be implemented using any suitable type of zero-voltage and / or zero-current sensing circuit configured to sense zero-current and / or zero-voltage crossings of the AC power supply waveform and generate a detection signal indicating the zero-crossing event and the associated direction of the current or voltage (e.g., a transition from negative to positive, or from positive to negative). Therefore, the zero-crossing sensor 840 is configured to receive an AC waveform as input, compare the input AC waveform with a zero reference voltage (e.g., line neutral voltage), and detect a positive-to-negative AC waveform transition when the AC waveform crosses the zero-point reference voltage, indicating waveform overlap. Each time a zero-crossing of the AC voltage waveform is detected, the zero-crossing detector will transition between logic "1" and logic "0" outputs.

[0074] The current sensor 850 is configured to detect the magnitude of the current consumed by the load 20 in the hot-line path of the solid-state circuit interrupter 800. The current sensor 850 can be implemented using any suitable type of current sensing circuit, including, but not limited to, current sensing resistors, current amplifiers, Hall effect current sensors, etc. The current sensor 850 is coupled to the switch controller 870 via one or more data acquisition and control lines 850-1.

[0075] The sensor 860 includes one or more optional sensors configured to detect potential hazardous environmental conditions (e.g., chemicals, gases, humidity, water, temperature, light, etc.) and generate sensor data indicating potentially hazardous environmental conditions. The sensor 860 is coupled to the switch controller 870 via one or more data acquisition and control lines 860-1.

[0076] The switch controller 870 works in conjunction with the zero-crossing sensor 840, the current sensor 850, and the sensor 860 to perform functions such as: detecting fault conditions (e.g., short-circuit faults, overcurrent faults, arcing faults, grounding faults, etc.), detecting hazardous environmental conditions (e.g., gas leaks, chemical leaks, fires, floods, etc.), and providing timing control for the opening and closing of switches 810 and 820 in response to detected fault conditions or hazardous environmental conditions to prevent arcing in the air-gap electromagnetic switch 820. The switch controller 870 generates a gate control signal applied to the gate terminal (G) of the solid-state switch 810 to place the solid-state switch 810 in an on or off state. In some embodiments, in response to fault conditions (e.g., short-circuit faults, overcurrent faults, and other faults or hazards) detected by the switch controller 870 through analysis of sensor data obtained from the current sensor 850 and / or other sensors 860, the switch controller 870 generates a gate control signal to put the solid-state switch 810 into an off state.

[0077] The switch controller 870 can be implemented using a processor configured to process sensor data and implement the switch control timing protocol discussed herein for controlling the switches 810 and 820. Furthermore, the switch controller 870 can implement circuitry for converting the sensor data into a suitable format for processor processing. The switch controller 870 may include an RF transceiver capable of wirelessly communicating with remote nodes, devices, systems, etc., to support remote monitoring and detection of fault conditions and to receive remote commands controlling the solid-state circuit interrupter 800. The processor may include a central processing unit, microprocessor, microcontroller, application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), and other types of processors, as well as portions or combinations of such processors capable of performing processing functions based on software, hardware, firmware, etc. In other embodiments, the solid-state circuitry of various components of the circuit interrupter 800 (such as 830, 840, and 870) may be implemented as a system-on-a-chip on a single die.

[0078] To prevent arcing between the electrical contacts of the electromagnetic switch 820, the switch controller 870 is configured to place the solid-state switch 810 in the closed state before placing the air-gap electromagnetic switch 820 in the open or closed state. However, in Figure 8 In this configuration, even if the solid-state switch 810 is in the off state, assuming the air-gap electromagnetic switch 820 is in the closed state, when the AC power waveform of the AC power supply 10 is in the negative half-cycle (i.e., when line heat 11 is negative and line neutral 12 is positive), the body diode 810-1 of the solid-state switch 810 will allow negative current to flow from the load 20 to the AC power supply 10. In fact, in this configuration, during the negative half-cycle, the body diode 810-1 is forward biased, allowing negative current to flow from the load 20 to the AC power supply 10 even when the solid-state switch 810 is in the off state.

[0079] In this scenario, if the air-gap electromagnetic switch 820 is disconnected during the negative half-cycle of the AC power supply waveform, the flow of negative current will generate an arc between the electrical contacts of the air-gap electromagnetic switch 820. To avoid generating such an arc, the switch controller 870 is configured to keep the solid-state switch 810 in the off state, then track sensor data obtained from the zero-crossing sensor 840 to determine the polarity of the AC voltage and / or current on the line side (e.g., line heat 11) of the solid-state circuit interrupter 800, and open the air-gap electromagnetic switch 820 when the polarity of the AC voltage and / or current on the line side is determined to be positive (e.g., the AC power supply voltage waveform is in the positive half-cycle). When, at a given time, the switch controller 870 determines that the polarity of the AC voltage and / or current on the line side is negative (e.g., the AC power supply voltage waveform is in the negative half-cycle), the switch controller 870 will not open the air-gap electromagnetic switch 820, but will postpone opening the air-gap electromagnetic switch 820 until the zero-crossing sensor 840 detects the next positive transition zero crossing. Reference will now be made to... Figure 9A , 9B The switching timing control implemented by the switch controller 870 is discussed in further detail in section 10.

[0080] Figure 9A Instructions for input Figure 8 The power supply voltage waveform on the line side of the solid-state circuit interrupter 800. Specifically, Figure 9A An input voltage waveform 900 is described, representing the power supply voltage waveform of the AC power supply 10. The input voltage waveform 900 includes a positive half-cycle 902, a negative half-cycle 904, and zero-voltage crossover 910 at times T0, T1, T2, T3, and T4. When the solid-state switch 810 is in the ON state and the air-gap electromagnetic switch 820 is in the OFF state, the input voltage waveform 900 is applied to the load hot-line 21 of the load 20. When the switch controller 870 determines that the power supply should be disconnected from the load 20, the switch controller 870 generates a gate control signal, which is applied to the gate terminal G of the solid-state switch 810 to turn the solid-state switch 810 OFF.

[0081] Figure 9B This describes the situation when the solid-state switch 810 is in the off state and the air-gap electromagnetic switch 820 is in the closed state. Figure 8 The output voltage waveform 920 on the load side of the solid-state circuit interrupter 800 is shown in the figure. In this state, during the negative half-cycle 904 of the input voltage waveform 900, the body diode 810-1 of the solid-state switch 810 is forward biased, which rectifies the input voltage waveform 900 and obtains... Figure 9BThe output voltage waveform 920 shown has a portion 922 corresponding to the positive half-cycle 902 of the input waveform 900, which is 0V, and a portion 924 of the output voltage waveform 920 tracks the voltage of the negative half-cycle 904 of the input waveform 900. In this case, during each negative half-cycle 924, a negative current flows from the load 20 to the AC power supply 10 until the air-gap electromagnetic switch 820 is turned off.

[0082] As described above, after the solid-state switch 810 is turned off, the switch controller 870 processes the sensor data received from the zero-crossing sensor 840 to determine when there is little or no current in the line thermal path, and then generates a control signal to disconnect the air gap electromagnetic switch 820 to completely disconnect the power supply to the load 20, while preventing or otherwise mitigating any arcing that may form in the air gap switch 820.

[0083] For example, in Figure 9A and 9B During the time interval T0 to T1, it is assumed that the solid-state switch 810 is in the off state. In this example, the switch controller 870 will detect the next zero-voltage crossover of the input waveform 900 at T1 as a negative transition zero-voltage crossover 910, and then wait for the next positive transition zero-voltage crossover 910 at T2 before turning off the air-gap electromagnetic switch 820 to ensure that no current flows in the line thermal path between the load 20 and the AC power supply 10 when the air-gap electromagnetic switch 820 is turned off.

[0084] It should be understood that the exemplary voltage waveforms 9A and 9B represent the load 20 with a power factor of approximately one (1), assuming that the AC voltage waveform and the current consumed by the load 20 are in phase. In this case, the zero-voltage crossover is assumed to be a zero-current crossover. However, if the power factor of the load 20 is less than 1 (e.g., a capacitive or inductive load), the voltage waveform and the current consumed by the load 20 will be out of phase. Therefore, the zero-crossing sensor 840 may include a zero-current crossover detector to determine a zero-current crossover or a positive transition zero-current crossover of the current waveforms on the line side of the switches 820 and 810, to ensure that no positive current flows in the line thermal path before the air-gap electromagnetic switch 820 is disconnected.

[0085] Figure 10 According to one embodiment of this disclosure, by Figure 8 A flowchart illustrating the switching control process implemented by the switch controller 870 of the solid-state circuit interrupter 800. Figure 10The switching control process represents a non-limiting exemplary embodiment for restoring utility power or for manually, automatically, or remotely activating control to activate the solid-state interruptor 800 (block 1000). In this example, it is assumed that the solid-state switch 810 is in the off state and the air-gap electromagnetic switch 820 is in the closed state.

[0086] Before closing the air-gap electromagnetic switch 820 (box 1004), the switch controller 870 waits to detect a suitable zero-crossing (box 1002). While ideally, a voltage and / or current zero-crossing event is waited for before closing the air-gap electromagnetic switch 820, those skilled in the art will understand that this is not a mandatory condition for closure. The zero-crossing event can be a positive transition zero-crossing event or a negative transition zero-crossing event. As described above, in some embodiments, preferably, the air-gap electromagnetic switch 820 is closed at the zero-crossing of the upcoming half-cycle, wherein the body diode (e.g., diode 810-1) of the solid-state switch (e.g., switch 810) is not forward-biased and conductive. For example, in Figure 8 In an exemplary embodiment, the body diode 810-1 of the solid-state switch 810 is reverse-biased and non-conductive during the positive half-cycle of the power supply voltage waveform of the AC power supply 10. In such an embodiment, it is ideal to place the air-gap electromagnetic switch in a closed state upon detection of a positive transition (current or voltage) zero-crossing event (block 1004). In other embodiments, depending on the MOSFET type used for the solid-state switch and the associated body diode, it may be ideal to close the solid-state switch upon detection of a negative transition (current or voltage) zero-crossing event.

[0087] When the air-gap electromagnetic switch 820 is closed, the switch controller 870 continues to generate a gate control signal to put the solid-state switch 810 into the ON state (block 1006). After the air-gap electromagnetic switch 820 is closed, the solid-state switch 810 can be turned on at any time. For example, the solid-state interruptor circuit 800 can operate in a "standby" mode, wherein the air-gap electromagnetic switch 820 remains closed, and the switch controller 870 waits for a trigger event (e.g., a remote command) to occur to continue activating the solid-state switch 810.

[0088] When both switches 810 and 820 are activated, the switch controller 870 enters a standby state, awaiting an event or command to interrupt the circuit connection between the power supply and the load (block 1008). During the standby period, the solid-state switch 810 and the air-gap electromagnetic switch 820 remain active (block 1010). The event may be a given fault condition or hazardous condition determined by the switch controller 870 through processing sensor data received from various sensors 850 and 860. The command may be a manual or automatic command to interrupt the circuit connection.

[0089] Upon detecting a fault or hazardous condition (a positive judgment in block 1008) or responding to a manual or automatic command to interrupt the circuit, the switch controller 870 generates a gate control signal to place the solid-state switch 810 in the off state (block 1012). The switch controller 870 then continues processing data from the zero-crossing sensor 840 to detect a target zero-crossing event (e.g., a positive transition zero-crossing event) in the line thermal path (block 1014), and in response to detecting the target zero-crossing event (a positive judgment in block 1014), the switch controller 870 generates a switch control signal to place the air-gap electromagnetic switch 820 in the off state (block 1016).

[0090] The switch controller 870 will enter a standby state (block 1018) to await a fault event or hazardous condition that needs to be cleared, and will keep the solid-state and air-gap electromagnetic switches in an inactive state (block 1020). When the fault event or hazardous condition is cleared (a positive judgment in block 1018), or when the switch controller 870 otherwise receives a manual or remote command instructing the reconnection of power and load, the control process returns to block 1000, whereby the switch controller 870 continues to reactivate the air-gap and solid-state switches, thereby reconnecting power and load. It should be understood that, although Figure 10 The process does not explicitly include process steps for zero-crossing detection before opening and closing the solid-state switch 810. However, those skilled in the art will recognize and understand that in some applications, the solid-state switch 810 can be turned on and off at timed intervals by voltage or current zero-crossing events as needed.

[0091] Figure 11A According to one embodiment of this disclosure, it is possible to Figure 8 A schematic block diagram of the AC-DC converter circuit 1100 implemented in the solid-state circuit interrupter 800 is shown. The AC-DC converter circuit 1100 includes an architecture that does not require a rectifier to generate DC voltage. The AC-DC converter circuit 1100 includes a surge protection circuit 1110, a sampling circuit 1120, a switch drive circuit 1130, a control switch and clamping circuit 1140, a storage circuit 1150, a voltage regulator circuit 1160, and a current isolation circuit 1170. The AC-DC converter circuit 1100 generates a DC power supply voltage applied to the load circuit 1102.

[0092] The surge protection circuit 1110 is configured to limit the input current of the AC-DC converter circuit 1100. The sampling circuit 1120 is configured to sample the AC power supply voltage waveform of the AC power supply 110. The sampling circuit 1120 outputs the sampled voltage to the switch drive circuit 1130. The switch drive circuit 1130 is configured to apply a control voltage to the control switch and clamping circuit 1140. The control switch and clamping circuit 1140 is configured to supply power to the storage circuit 1150 in response to the control voltage applied by the switch drive circuit 1130. The storage circuit 1150 includes a voltage storage element (such as a capacitor) configured to store the DC voltage applied to the voltage regulator circuit 1160. The voltage regulator circuit 1160 is configured to generate a stable DC power supply voltage to the load circuit 1102.

[0093] In some embodiments, the switch drive circuit 1130 receives a feedback voltage 1180 from the storage circuit 1150 and generates a control voltage applied to the control switch and clamping circuit 1140 based at least in part on the feedback voltage 1180. In some embodiments, the feedback voltage 1180 may be eliminated, and the AC-DC converter circuit 1100 operates as a feedforward converter, wherein the storage elements of the storage circuit 1150 are controlled by the feedforward elements 1120, 1130, and 1140.

[0094] In some embodiments, the AC-DC converter circuit 1100 implements a feedback control circuit 1190 from the load circuit 1102 to the switch drive circuit 1130 to support feedforward and feedback control. In some embodiments, the balance between feedforward and feedback control is determined by the feedback voltage 1180 and the selection of components in the sampling circuit 1120. In some embodiments, the balance between feedforward and feedback control is configured based on the resistive elements in the sampling circuit 1120 and the feedback voltage 1180. In other embodiments, variable elements are used to adjust the feedforward and feedback control. In these embodiments, the feedback circuit 1190 will include current insulation between the switch drive circuit 1130 and the load circuit 1102.

[0095] Figure 11B According to one embodiment of this disclosure, Figure 11A A schematic circuit diagram of an AC-DC converter. Figure 11BIn an exemplary embodiment, the surge protection circuit 1110 includes a first input resistor 1111 connected to the line thermal 11 of the AC power supply 10 and a second input resistor 1112 connected to the line neutral 12 of the AC power supply 10. In other embodiments, for high-power and high-efficiency applications, the surge protection circuit 1110 includes a switching element configured to allow current to flow through resistors 1111 and 1112 during startup and then bypass resistors 1111 and 1112 when a steady-state operating condition is reached. In other embodiments, the surge protection circuit 1110 includes first and second inductor elements replacing the first and second resistors 1111 and 1112.

[0096] Therefore, the sampling circuit 1120 includes multiple resistors 1121, 1122, 1123, and 1124 connected to nodes N1, N2, N3, and N4 as shown in the figure. Resistors 1121, 1122, and 1123 form a voltage divider network for sampling the input AC waveform, wherein the voltage divider network includes a feedback node N2 and an output node N3. Resistor 1124 is connected between the feedback node N2 and the output node N4 of the storage circuit 1150 to provide a feedback voltage from the storage capacitor 1152. The switch drive circuit 1130 includes a resistor 1131 connected between nodes N1 and N5, and a switching element 1132. The control switch and clamping circuit 1140 includes a control switching element 1141, a resistor 1142, and a Zener diode 1143. The storage circuit 1150 includes a diode 1151 and a storage capacitor 1152. The voltage regulator circuit 1160 includes a switching element 1161, a resistor 1162, a Zener diode 1163, and a capacitor 1164.

[0097] In some embodiments, the switching elements 1132, 1141, and 1161 include those having, as shown in the figure Figure 11B The diagram shows an n-type enhancement MOSFET device with gate (G), drain (D), and source (S) terminals. In other embodiments, the switching elements 1132, 1141, and 1161 can be implemented using bipolar transistors or microelectromechanical switches. Figure 11B As shown, the switching element 1143 includes a gate terminal G, a drain terminal D, and a source terminal S. The gate terminal G is connected to the output node N3 of the voltage divider network of the sampling circuit 1120. The drain terminal D is connected to the output node N5 of the switch drive circuit 1130, and the source terminal S is connected to the output node N3 of the surge protection circuit 1110. The drain terminal D of the switching element 1132 is coupled to the output node N1 of the surge protection circuit 1110 through a resistor 1131.

[0098] The control switch 1141 includes a drain terminal D, a gate terminal G, and a source terminal S. The drain terminal D is connected to the output node N1 of the surge circuit 1110, the gate terminal G is connected to the output node N5 of the switch drive circuit, and the source terminal S is connected to the input of the storage circuit 1150 (i.e., the anode of diode 1151). A Zener diode 1143 is connected between the gate terminal G and the source terminal S of the control switch 1141. The cathode of the Zener diode 1143 is connected to the gate terminal G of the control switch 1141, and the anode of the Zener diode 1143 is connected to the source terminal S of the control switch 1141.

[0099] The switching element 1161 of the voltage regulator circuit 1160 includes a drain terminal D, a gate terminal G, and a source terminal S. The drain terminal D is connected to the output node N4 of the storage circuit 1150. The gate terminal G is connected to node N7 between the resistor 1162 and the Zener diode 1163. The source terminal S is connected to the output node N8 of the voltage regulator circuit 1160. The capacitor 1164 is connected between the output node N8 of the voltage regulator circuit 1160 and the output node N6 of the surge protection circuit 1110.

[0100] The resistor 1124 (or sensing resistor) is connected between the output node N4 of the storage circuit 1150 to provide a feedback voltage, which is applied to the feedback node N2 of the sampling circuit 1120 through the feedback resistor 1124. The feedback path provided by the connection of the feedback resistor 1124 between nodes N4 and N2 provides, for example, Figure 11A An exemplary embodiment of the feedback voltage 1180 shown herein utilizes part of the charge of the storage capacitor 1152 to generate a control voltage at the output node N3 of the sampling circuit 1120, which is connected to the gate terminal G of the switching element 1132 of the switch drive circuit 1130.

[0101] The switching element 1132 is driven by a gate control voltage generated at the output node N3 of the voltage divider network of the sampling circuit 1120. The selection of the switching element 1132 controls the operation of the control switch 1141 of the switch drive circuit 1130. By selecting the resistance values ​​of resistors 1121, 1122, 1123, and 1124, the voltage applied to the gate terminal G of the switching element 1132 in the switch drive circuit 1130 at node N3 of the voltage divider network will turn the switching element 1132 on and off, thereby synchronously turning the control switch 1141 on and off. This drives the control switch 1141 to output a pre-selected timing output pulse to charge the storage capacitor 1152.

[0102] Based on a pre-selected value of the Zener voltage (i.e., reverse breakdown voltage) of the Zener diode 1143, the peak output current of the control switch 1141 is clamped to the pre-selected value, wherein the maximum gate-source voltage (V) GS The voltage is limited by the Zener voltage of the Zener diode 1143. The pulse output of the control switch 1141 turns on the diode 1151 and provides charge to node N4 to charge the storage capacitor 1152. The feedback provided by the resistor 1124 connected between the output node N4 of the storage circuit 1160 and the feedback node N2 of the sampling circuit 1120 is used to drive the switch drive circuit 1130 to keep the storage capacitor 1152 with a constant charge.

[0103] Synchronized with the AC voltage input, the switching element 1132 and the control switch 1141 are activated (opened or closed). The AC-DC converter circuit 1100 provides a low-voltage output with pulse modulation at the frequency of the input AC source. The switches 1132 and 1141 are activated (opened or closed) near the zero-crossing voltage of the AC source within the threshold voltage range of the switches 1132 and 1141. The output node N4 of the storage circuit 1150 is applied to the input of the voltage regulator circuit 1160, and then to the load circuit 1102. The capacitor 1164 provides storage capacity to buffer and thus smooth the output from the AC-DC converter 1100 to the load circuit 1102.

[0104] In short, such as Figure 11A and 11B The exemplary AC-DC converter circuit 1100 shown includes a surge protection circuit 1110, a voltage sampling circuit 1120, a switch driver circuit 1130, a control switch and clamping circuit 1140, a storage circuit 1150, and a voltage regulator circuit 1160. The selection of components in the voltage sampling circuit 1120 determines the timing of the switch driver 1130. The selection of components in the control switch and clamping circuit 1140 determines the peak voltage and current of the output pulse. Power output is controlled by selecting the peak current and pulse timing. Pulse timing is selected using the storage element 1152 based on feedback from the voltage sampling circuit 1120. The AC-DC converter circuit 1100 operates synchronously with the AC voltage waveform of the AC power supply 110.

[0105] While exemplary embodiments have been described herein with reference to the accompanying drawings, it should be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be made therein by those skilled in the art without departing from the scope of the appended claims.

Claims

1. A circuit interrupter, comprising: A solid-state switch is connected in series between the line input and the load output of the circuit interrupter and is configured to be in one of (i) an on state and (ii) an off state, wherein being in the on state provides an electrical connection in the electrical path between the line input and the load output. and A mode control circuit, configured to execute a first control mode and a second control mode to control the operation of the circuit interrupter; In the first control mode, the mode control circuit is configured to: (i) generate an on-threshold voltage during circuit interrupter power-up using current derived from the input power supply when applied to the line input of the circuit interrupter; (ii) couple the control terminal of the solid-state switch to the second terminal of the solid-state switch during circuit interrupter power-up to keep the solid-state switch in the off state until the on-threshold voltage is generated to a constant voltage level; and (iii) disconnect the control terminal of the solid-state switch from the second terminal of the solid-state switch, thereby applying the constant voltage level of the on-threshold voltage to the control terminal of the solid-state switch to place the solid-state switch in the on state; and In the second control mode, the mode control circuit is configured to couple the control terminal of the solid-state switch to the second terminal of the solid-state switch to interrupt the on-threshold voltage applied to the control terminal of the solid-state switch, thereby placing the solid-state switch in the off state.

2. The circuit interrupter according to claim 1, wherein the mode control circuit comprises: The self-biasing circuit includes a clamping circuit and a first control switch; The clamping circuit is configured to generate the turn-on threshold voltage using the current derived from the input power supply when applied to the line input of the circuit interrupter during power-on. and In response to the activation of the first control switch, the first control switch is configured to couple the control terminal of the solid-state switch to the second terminal of the solid-state switch to keep the solid-state switch in the off state until the on threshold voltage is generated to the constant voltage level.

3. The circuit interrupter according to claim 2, wherein the clamping circuit comprises a capacitor and a Zener diode connected in parallel.

4. The circuit interrupter of claim 2, wherein the self-biasing circuit includes a resistor-capacitor network coupled to a control terminal of the first control switch, wherein the resistor-capacitor network is charged during power-up of the circuit interrupter using a current derived from the input power supply at the line input terminal when applied to the circuit interrupter, wherein the resistor-capacitor network is configured to have a resistor-capacitor time constant corresponding to a period of time not less than the period of time required for the turn-on threshold voltage to generate the constant voltage level during power-up of the circuit interrupter.

5. The circuit interrupter of claim 2, wherein the self-biasing circuit includes an operational amplifier having an input connected to the clamping circuit and an output connected to a control terminal of the first control switch, wherein the operational amplifier is configured to keep the first control switch in an ON state during the generation of the ON threshold voltage and to turn the first control switch in an OFF state after the generation of the ON threshold voltage, thereby controlling the operation of the first control switch.

6. The circuit interrupter of claim 2, wherein the mode control circuit includes a second control switch configured to couple the control terminal of the solid-state switch to the second terminal of the solid-state switch and interrupt the on-threshold voltage applied to the control terminal of the solid-state switch, thereby placing the solid-state switch in a closed state in response to activation of the second control switch.

7. The circuit interrupter of claim 6 further includes a sensor circuit configured to generate a control signal to activate the second control switch in response to the sensor circuit detecting a condition that guarantees placing the solid-state switch in the off state.

8. The circuit interrupter of claim 7, wherein the sensor circuit includes a current sensor configured to sense current flowing in the electrical path between the line input and the load output, and to detect fault conditions, wherein the fault conditions include one of a short-circuit fault condition, an overcurrent fault condition, an arc fault condition, and a ground fault condition.

9. The circuit interrupter of claim 7, wherein the sensor circuit includes an environmental sensor circuit configured to sense hazardous environmental conditions.

10. The circuit interrupter of claim 9, wherein the environmental sensor circuit comprises one or more of the following: (i) a chemically sensitive detector configured to detect the presence of hazardous chemicals, (ii) a gas-sensitive detector configured to detect the presence of hazardous gases, (iii) a temperature sensor configured to detect temperature, (iv) a piezoelectric detector configured to detect vibration, and (v) a humidity sensor configured to detect a humid environment.

11. The circuit interrupter of claim 7, wherein the second control switch comprises a phototransistor, and wherein the sensor circuit optically couples the phototransistor to activate the phototransistor in response to a light control signal.

12. The circuit interrupter of claim 6, wherein the second control switch comprises a phototransistor, and wherein the phototransistor is activated in response to a light control signal.

13. A circuit breaker, comprising the circuit interrupter according to claim 1.

14. An electrical socket device comprising a circuit interrupter according to claim 1.

15. A light switch comprising the circuit interrupter according to claim 1.

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