High-voltage discharge circuit for battery power supply and electric flame cooker

Abstract

The application discloses a high-voltage discharge circuit and an electric flame stove suitable for a battery power supply, which comprises an inverter driving module, a step-up transformer T1, at least three groups of active bridge rectifier modules and discharge modules corresponding to the active bridge rectifier modules. The application combines the active bridge rectifier module driving, voltage / current double closed-loop feedback and real-time PWM signal output control of the control chip U1, eliminates the current difference of each discharge branch, solves the problem of uneven branch current, eliminates the circulating current and reactive power loss among the branches, discards the diode in the voltage doubling rectifier circuit and the discharge resistor of the resonance circuit in the prior art, adopts the active bridge rectifier module driving, dynamically adjusts the PWM signal through the low ESR characteristic of the capacitor C1 and the closed-loop control, avoids the additional power loss, controls the circuit working temperature below 85 DEG C and increases the continuous use life of the components in the circuit.

Description

Technical Field

[0001] This invention specifically relates to an electric flame stove. Background Technology

[0002] Electric flame stoves employ multiple high-voltage discharge devices (connected in parallel with positive and negative electrodes in a closed-circuit discharge configuration). Each device generates an electric field by blasting gas flow through high voltage. The gas flow collides with electrons in this electric field, ionizing the gas molecules and exciting plasma. This plasma, with a temperature exceeding 1000 degrees Celsius, is used to heat cookware. Currently, electric flame stoves on the market are also known as electric fire stoves, electric fire starter stoves, electric flame stoves, electric gas stoves, electric open flame stoves, plasma stoves, etc. All of these stoves utilize the working principle of high-voltage breakdown to excite plasma for heating cookware.

[0003] With the increasing demand for outdoor cooking, electric flame stoves typically require direct current from batteries or electric vehicles. Therefore, it is necessary to develop an electric flame stove with a dedicated direct current input.

[0004] In existing technologies (such as) Figure 1 As shown in the figure, high-voltage AC power output from a transformer is typically rectified into DC power with twice the voltage by a parallel bridge voltage multiplier rectifier circuit, and then the doubled DC power is delivered to multiple corresponding high-voltage discharge devices.

[0005] The output voltage of a bridge voltage multiplier rectifier depends on the upper limit of capacitor charging and the unidirectional conductivity of the diode. However, in actual circuits, even if capacitors or diodes of the same parameter type are used, the component parameters of any two parallel branches cannot be completely identical. For example, there are still slight differences in capacitance, leakage resistance, and equivalent series resistance (ESR) between capacitors, and slight differences in forward voltage drop and reverse leakage current between diodes. However, the load of an electric flame stove is essentially ionized into plasma by breaking down air under high voltage. The impedance of plasma (high conductivity) is much lower than that of air (insulator), and the impedance of the load still fluctuates with the flow of plasma and gas after breakdown. Therefore, the high-frequency fluctuation of the load impedance amplifies the differences in the current supply capacity of each parallel branch. This results in huge differences in the current of each branch. For example, a branch with a fast response (fast capacitor discharge speed and low diode impedance) can quickly adapt to state switching, resulting in excessive current and excessive power; while a branch with a slow response (slow capacitor discharge speed and high diode impedance) has insufficient current and insufficient power, failing to provide enough current to maintain load conductivity. Meanwhile, since the negative terminals of each branch are connected to the common connection point or the common ground, the current will flow between the branches, forming a "circulating current". This results in significant reactive power loss, which may prevent some branches from breaking down the insulating gas to achieve ignition or maintain a large current "combustion", thus affecting the stability of the electric flame stove.

[0006] For example, invention application No. 2024105774981 proposes a boost circuit for an electric gas stove, including: a first electrode P2, a second electrode P4, an input terminal P1, an input terminal P3, a first rectifier module, a second rectifier module, a first boost module, and a second boost module; the first rectifier module and the second rectifier module are both multiple capacitors of the same specification connected in series, the first boost module and the second boost module are both multiple boost diodes of the same specification connected in series, and the protection module is a resistor and a capacitor connected in parallel.

[0007] According to this invention application, each diode has a small impedance. Connecting multiple diodes in parallel will amplify the impedance. At the same time, in order to prevent overvoltage in the circuit and ensure circuit stability, the resistor discharges the excessive voltage in the circuit. This not only leads to energy loss, but also easily causes current control divergence, resulting in oscillation. Summary of the Invention

[0008] To overcome the shortcomings mentioned above, the present invention aims to provide a technical solution that can solve the above problems.

[0009] A high-voltage discharge circuit suitable for battery power supply, used in an electric flame stove, includes: an inverter drive module, a step-up transformer T1, at least three sets of active bridge rectifier modules, and a discharge module corresponding to the active bridge rectifier modules; the discharge module consists of a discharge electrode and a return electrode, the positive output terminal of the active bridge rectifier module is electrically connected to the corresponding discharge electrode, and the negative output terminal of the active bridge rectifier module is electrically connected to the corresponding return electrode; the active bridge rectifier module is a bridge drive circuit composed of switching transistors Q1 / Q2 / Q3 / Q4, and the switching transistors Q1 / Q3 and Q2 / Q4 are alternately turned on;

[0010] Preferably, the inverter drive module includes switching transistors Q5 / Q6 / Q7 / Q8, and the switching transistors Q5 / Q6 / Q7 / Q8 are connected in a bridge configuration.

[0011] Preferably, the active bridge rectifier module further includes a control chip U1, and the current sampling pin of the control chip U1 is connected to the positive output terminal of the active bridge rectifier module through a resistor R2.

[0012] Preferably, the gates of the multiple PWM output pins of the control chip U1 are respectively connected to the gates of the switching transistors Q1 / Q2 / Q3 / Q4;

[0013] Preferably, the two ends of the secondary coil of the step-up transformer T1 are connected to the two voltage sampling pins of the control chip U1 through current transformers T2 / T3 respectively;

[0014] Preferably, the positive and negative output terminals of the active bridge rectifier module are further connected in parallel with a capacitor C1;

[0015] An electric flame stove, comprising a high-voltage discharge circuit suitable for a storage battery power source as described in any of the preceding claims.

[0016] Compared with the prior art, the advantages of the present invention are:

[0017] This invention combines active bridge rectifier module drive, voltage / current dual closed-loop feedback, and real-time output PWM signal control by control chip U1 to eliminate the current difference between each discharge branch, avoid some branches burning out due to excessive power, and prevent other branches from failing to maintain discharge, thus solving the problem of uneven branch current and eliminating circulating current and reactive power loss between branches.

[0018] This invention eliminates the diodes and bleeder resistors in the resonant circuit of the voltage doubler rectifier circuit in the prior art. It adopts an active bridge rectifier module for driving and dynamically adjusts the PWM signal through the low ESR characteristics of capacitor C1 and closed-loop control to avoid additional power loss. This keeps the circuit operating temperature below 85°C and increases the continuous service life of the components in the circuit.

[0019] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 It is a circuit diagram of existing technology.

[0022] Figure 2 This is a circuit diagram illustrating the working principle of the present invention.

[0023] Figure 3 This is a circuit diagram of a single active bridge rectifier module and transformer. Detailed Implementation

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] In the description of this invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0026] Furthermore, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components; they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0028] Please see Figures 1-2 In this embodiment of the invention, a high-voltage discharge circuit suitable for battery power supply is used in an electric flame stove, comprising: an inverter drive module 100, a step-up transformer T1, at least three sets of active bridge rectifier modules 200, and a discharge module corresponding to each active bridge rectifier module 200. The discharge module consists of a discharge electrode E1 and a return electrode E2. The positive output terminal 1 of the active bridge rectifier module 200 is electrically connected to the corresponding discharge electrode E1, and the negative output terminal 2 of the active bridge rectifier module 200 is electrically connected to the corresponding return electrode E2.

[0029] Based on the core problems of "uneven current distribution, large circulating current loss, and high oscillation risk" in the existing technology, this invention achieves precise control of each discharge branch through the active bridge rectifier module 200 structure. The active bridge rectifier module 200 is a bridge drive circuit composed of switching transistors Q1 / Q2 / Q3 / Q4, with switching transistors Q1 / Q3 and Q2 / Q4 conducting alternately.

[0030] In this embodiment, as Figure 3 As shown, the active bridge rectifier module 200 also includes a control chip U1. The two ends of the secondary coil of the step-up transformer T1 are connected to the two voltage sampling pins of the control chip U1 through current transformers T2 / T3 respectively.

[0031] For example, the control chip U1 can be an IR2113 high-voltage bridge driver chip (with built-in overcurrent protection pin, supporting PWM frequency 0-200kHz). It senses the voltage across the secondary coil of the step-up transformer T1 through the current transformers T2 / T3, and then steps down the high-voltage signal at a ratio of 1:100 before inputting it to the voltage sampling pin of the control chip U1. It monitors the branch input voltage in real time. Based on the voltage sampling signal, the control chip U1 automatically adjusts the PWM drive signal output to the switching transistors Q1 / Q3 or Q2 / Q4, so that the switching transistors Q1 / Q3 or Q2 / Q4 alternately conduct at a frequency that synchronously follows the voltage change across the secondary coil of the step-up transformer T1.

[0032] In this embodiment, the switching transistors Q1 / Q3 and Q2 / Q4 of the active bridge rectifier module 200 are alternately turned on to realize the "AC to DC" conversion. The positive output terminal 1 and the negative output terminal 2 of the active bridge rectifier module 200 are also connected in parallel with capacitor C1 to smooth the pulsating DC power. When the secondary winding of the step-up transformer T1 is "positive at the top and negative at the bottom", the control chip U1 outputs a PWM signal, which turns on the upper bridge arm switches Q1 and Q3 and turns off the lower bridge arm switches Q2 and Q4. A closed loop is formed through the switches Q1 and Q3, providing a stable high voltage to the discharge electrode E1. When the secondary winding of the step-up transformer T1 is "negative at the top and positive at the bottom", the control chip U1 outputs a PWM signal, which turns on the upper bridge arm switches Q2 and Q4 and turns off the lower bridge arm switches Q1 and Q3. A closed loop is formed through the switches Q2 and Q4, providing a stable voltage difference between the discharge electrode E1 and the return electrode E2. Due to the switching gap, there is ripple in the output voltage. The capacitor C1 discharges to replenish the energy, providing a stable high voltage DC current to the discharge electrode E1.

[0033] In this embodiment, the current sampling pin of the control chip U1 is connected to the positive output terminal 1 of the active bridge rectifier module 200 through resistor R2; the multiple PWM output pins of the control chip U1 are connected to the gates of switching transistors Q1 / Q2 / Q3 / Q4 respectively. Resistor R2 collects the operating current of the discharge module and converts the current signal into a voltage signal, which is then input to the current sampling pin of the control chip U1. Before the gas is broken down, when the operating current is less than the preset current threshold, the control chip U1 dynamically adjusts the PWM duty cycle to increase the current to stabilize the current; when the gas is broken down and plasma is formed, the load impedance fluctuation causes the operating current to exceed the preset current threshold, and the control chip U1 immediately reduces the duty cycle to maintain current stability.

[0034] The active bridge rectifier module 200 outputs a stable operating voltage and current, ensuring that the operating voltage and current of the discharge module remain stable, thus achieving stable power output.

[0035] This invention abandons the existing "voltage doubler rectifier parallel" scheme and adopts "active bridge rectifier module 200" to fundamentally solve the problem of uneven current and circulating current caused by differences in component parameters. This invention introduces a voltage / current dual sampling feedback mechanism and dynamically adjusts the PWM signal through the control chip U1 to achieve precise and stable discharge current, which is different from the existing technology design of "no independent control and passive discharge".

[0036] In another embodiment, the inverter drive module 100 includes switching transistors Q5 / Q6 / Q7 / Q8, which are connected in a bridge configuration to provide inverter drive for the battery. The battery typically uses a 48V voltage. This embodiment is a conventional configuration in the prior art and will not be described in detail here.

[0037] In another embodiment of the present invention, the control method of the active bridge rectifier module 200 is as follows:

[0038] The system has preset voltage threshold, first current threshold, and second current threshold, and the control chip U1 collects real-time voltage and current signals.

[0039] Based on the initial duty cycle, generate the target PWM signal for control chip U1;

[0040] Based on the sampled voltage of current transformers T2 / T3, the target PWM signal switching transistors Q1 / Q3 and Q2 / Q4 operate in an "alternating conduction" mode to achieve AC→DC conversion;

[0041] Based on the sampled current of resistor R2, the duty cycle of the PWM signal is adjusted in real time to adapt to high-frequency fluctuations in load impedance.

[0042] In this embodiment, the method for adjusting the duty cycle of the PWM signal in real time is as follows: when the gas is broken down to produce plasma, the load impedance decreases, causing the current to increase, and the duty cycle of the PWM signal decreases, such as from 40% to 35%, reducing the conduction time, reducing the output power, and suppressing current overload; when the gas flows away from the plasma, the load impedance increases, causing the current to decrease, and the duty cycle of the PWM signal increases, increasing the conduction time, compensating for insufficient current, increasing the output power, and maintaining flame stability.

[0043] The core function of this strategy of adjusting the duty cycle of the PWM signal in real time is to dynamically adapt to the high-frequency impedance fluctuations of the plasma load, while eliminating the voltage and current differences between the parallel-connected branches, thus achieving dynamic and average distribution of the total power of the electric flame stove.

[0044] The present invention also proposes an electric flame stove, which includes a high-voltage discharge circuit suitable for a battery power supply as described above.

[0045] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A high-voltage discharge circuit suitable for battery power supply, used in an electric flame stove, characterized in that, include: A set of inverter drive modules, a set of step-up transformers T1, at least three sets of active bridge rectifier modules connected in parallel, and at least three sets of discharge modules corresponding to the active bridge rectifier modules; The discharge module consists of a discharge electrode and a return electrode. The positive output terminal of the active bridge rectifier module is electrically connected to the corresponding discharge electrode, and the negative output terminal of the active bridge rectifier module is electrically connected to the corresponding return electrode. The active bridge rectifier module is a bridge drive circuit composed of switching transistors Q1, Q2, Q3, and Q4, with switching transistors Q1 / Q3 and Q2 / Q4 alternately conducting. The active bridge rectifier module also includes a control chip U1, whose current sampling pin is connected to the positive output terminal of the active bridge rectifier module through a resistor R2. The multiple PWM output pins of the control chip U1 are respectively connected to the gates of switching transistors Q1, Q2, Q3 and Q4. The two ends of the secondary coil of the step-up transformer T1 are connected to the two voltage sampling pins of the control chip U1 through current transformers T2 and T3, respectively. Control method of active bridge rectifier module: preset voltage threshold, first current threshold, second current threshold, control chip U1 collects real-time voltage and current signals; Based on the initial duty cycle, the target PWM signal of the control chip U1 is generated; according to the sampled voltages of transformers T2 and T3, the target PWM signal is used to drive switches Q1 and Q2 to operate in alternating conduction mode, and to drive switches Q3 and Q4 to operate in alternating conduction mode, thereby realizing AC→DC conversion; according to the sampled current of resistor R2, the duty cycle of the PWM signal is adjusted in real time to adapt to high-frequency fluctuations in load impedance; The method for adjusting the duty cycle of the PWM signal in real time is as follows: When the gas is broken down to produce plasma, the load impedance decreases, causing the current to increase. The duty cycle of the target PWM signal decreases from 40% to 35%, reducing the conduction time, reducing the output power, and suppressing current overload. When the gas flows away from the plasma, the load impedance increases, causing the current to decrease. The duty cycle of the target PWM signal increases, increasing the conduction time, compensating for insufficient current, increasing the output power, and maintaining flame stability.

2. The high-voltage discharge circuit applicable to a storage battery power supply according to claim 1, characterized in that, The inverter drive module includes switching transistors Q5, Q6, Q7, and Q8, which are connected in a bridge configuration.

3. The high-voltage discharge circuit applicable to a storage battery power supply according to claim 2, characterized in that, A capacitor C1 is also connected in parallel between the positive and negative output terminals of the active bridge rectifier module.

4. An electric flame stove, characterized in that, The electric flame stove includes a high-voltage discharge circuit with a suitable battery power supply as described in any one of claims 1 to 3.

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