CN111835185A

CN111835185A - Alternating current source self-adaptive control circuit with different voltage levels and operation logic method

Info

Publication number: CN111835185A
Application number: CN201910322000.6A
Authority: CN
Inventors: 戴政; 孔小明; 祁本祥
Original assignee: Jiangsu Reya Electric Co ltd
Current assignee: Jiangsu Reya Electric Co ltd
Priority date: 2019-04-22
Filing date: 2019-04-22
Publication date: 2020-10-27

Abstract

The invention discloses an AC source self-adaptive control circuit with different voltage grades and an operation logic method, the circuit comprises a single-phase AC power supply, a single-phase rectification circuit, at least two series electrolytic capacitor groups and series electrolytic voltage balance resistor groups which form a group, a DC voltage detection circuit, an AC voltage detection circuit, a voltage doubling switch control circuit and a control CPU, wherein the AC input side of the circuit is provided with the AC voltage detection circuit, the DC side is provided with the DC voltage detection circuit, finally the rectification circuit side is provided with the voltage doubling switch and the voltage doubling switch control circuit, the control CPU carried in the circuit simultaneously detects the AC voltage value and the DC voltage value, the voltage doubling switch is controlled through logic operation to ensure that the rectified DC voltage is maintained in a preset working voltage range when different AC voltage grades are input, thereby providing stable DC power supply voltage for the output of the later stage.

Description

Alternating current source self-adaptive control circuit with different voltage levels and operation logic method

Technical Field

The invention relates to the field of circuit design of alternating current power supplies, in particular to an alternating current source self-adaptive control circuit with different voltage grades and an operation logic method.

Background

Generally, the alternating current power supply has various voltage modes, for example, the alternating current power supply in China has single-phase 220V and three-phase 380V, and the alternating current power supply in the United states has single-phase 115V and single-phase 230V. When a general electric appliance is designed, corresponding circuit design must be carried out on alternating current power supplies with different voltage grades in advance, but after the voltage grade of the power supply is changed, the electric appliance cannot adapt to the change of the voltage grade.

In order to solve the problem, some electrical appliances are designed to manually specify the voltage level of the alternating current power supply in a mode of switching, dialing or skipping and the like, so that the purpose of keeping the electrical appliances to work under different voltage levels is achieved. For example, a switch is arranged on a transformer circuit built in the electrical appliance to switch the transformation level, or a voltage-doubling rectifying circuit is arranged on a rectifying circuit built in the electrical appliance through the switch to ensure that the voltage of a post-stage circuit inside the electrical appliance is always kept at the design voltage, so that the purpose that the electrical appliance can stably work under alternating current power supplies with different power supply levels is achieved. Such electrical appliances, for example, hair dryers specially designed for overseas travel, are switched on and off with an ac voltage of 110V/220V.

However, this method is not only cumbersome to use, but also presents a significant safety hazard. When the specified input alternating current 110V class voltage, the electrical appliance is connected with the 220V alternating current, the direct current voltage of a post-stage circuit in the electrical appliance is too high, the circuit device is broken down and damaged, and a fire disaster or serious accidents such as personal injury and death are caused in more serious cases. When the input alternating current 220V grade is appointed, the electrical appliance is connected with the 110V alternating current, and the electrical appliance can cause various problems such as insufficient working voltage, insufficient power, serious heating and even fire and the like due to insufficient voltage of an internal post-stage circuit.

Disclosure of Invention

Aiming at the defects, the method fully considers the fact that when the electric appliance actually works, the turn-off/turn-on of the alternating current power supply, the voltage fluctuation and the like of the alternating current power supply can cause interference to the electric appliance and an internal circuit, especially, the invention provides a self-adaptive control circuit of alternating current sources with different voltage grades and an operation logic method thereof, when designing an AC power supply adaptive control circuit, two voltage detection means for simultaneously detecting AC input voltage and DC input voltage are provided, meanwhile, the CPU intelligently and automatically switches on or off the voltage-doubling rectifying circuit in the aspect of control through the operation logics such as whether the AC voltage and the DC voltage accord with the corresponding relation or not, therefore, the purpose that the electric appliance can automatically adapt to alternating current power supplies of different grades is achieved, and meanwhile, the safety of the electric appliance is also ensured.

In order to achieve the purpose, the invention adopts the following technical scheme:

the alternating current source adaptive control circuit with different voltage grades comprises a single-phase alternating current power supply, a single-phase rectification circuit, at least two series electrolytic capacitor groups which are taken as a group, a series electrolytic voltage balance resistor group, a direct current voltage detection circuit, an alternating current voltage detection circuit, a voltage doubling switch control circuit and a control CPU, wherein the alternating current voltage grade of the single-phase alternating current power supply is 110V or 220V, the alternating current voltage of the single-phase alternating current power supply is rectified by the single-phase rectification circuit to be converted into direct current voltage which is stored in the electrolytic capacitor groups, the DC voltage detection circuit inputs the detected DC voltage signal Vdc to the control CPU for the control CPU to sample the DC voltage, the AC voltage detection circuit inputs the detected AC voltage signal Vac to the control CPU for the control CPU to sample the AC voltage, and the voltage doubling switch control circuit are controlled by the control signal of the control CPU.

Further, the single-phase rectification circuit is composed of a rectification bridge.

Further, the direct voltage detection circuit is composed of a plurality of resistance voltage division circuits.

Furthermore, the alternating voltage detection circuit is composed of an alternating current transformer, and a rectifying filter composed of a diode and a resistance-capacitance device.

Furthermore, the alternating voltage detection circuit is composed of a plurality of resistance voltage division circuits, and a rectifying and filtering circuit composed of diodes and resistance capacitance components.

Further, the voltage-multiplying switch and the voltage-multiplying switch control circuit are composed of a relay and a relay drive circuit.

Furthermore, the voltage-multiplying switch and the voltage-multiplying switch control circuit are composed of a bidirectional semiconductor switch circuit composed of semiconductor switch devices of IGBT or MOSFET and a drive circuit.

The alternating current power supply source with different voltage levels is an adaptive control operation logic method, which comprises the following steps:

firstly, starting adaptive control of alternating current voltage, and disconnecting a voltage-multiplying switch;

step two, the control CPU samples the alternating voltage and the direct voltage at the same time and calculates average values respectively;

step three, the control CPU judges whether the alternating voltage is in the range of 110V or 220V grade threshold value;

if the alternating voltage is within the threshold range of the 110V grade, the control CPU calculates the proportion of the direct voltage and the alternating voltage and judges whether the proportion is within the threshold range, judges whether the direct voltage is within the corresponding threshold range, if so, controls the voltage doubling switch to be closed, and executes sampling of the alternating voltage and the direct voltage at regular time and judges whether the voltage is abnormal;

and step five, if the alternating voltage is in the threshold range of the 220V grade, the control CPU directly judges whether the direct voltage is in the corresponding threshold range, and if so, the control CPU directly performs sampling on the alternating voltage and the direct voltage at regular time and judges whether the alternating voltage and the direct voltage are abnormal.

Has the advantages that:

1. the self-adaptive control circuit of the invention can automatically correspond to AC power supplies with different voltage grades, an AC voltage detection circuit is arranged on the AC input side of the circuit, a DC voltage detection circuit is arranged on the DC side, and finally a voltage doubling switch and a voltage doubling switch control circuit are arranged on the side of the rectification circuit.

2. The self-adaptive control operation logic method of the invention simultaneously utilizes the information of two detection circuits of AC voltage and DC voltage to control the voltage doubling circuit on the premise of matching AC and DC sampling voltages; especially, the proportion calculation and check logic of the alternating voltage and the direct voltage can prevent the power supply voltage fluctuation interference and the electromagnetic noise interference, can prevent the misoperation when a single detection circuit fails from damaging circuits and devices, and ensures the safety of the whole circuit.

3. The invention adopts the CPU to carry out self-adaptive control, so that the electrical appliance has intellectualization, the reliability of the electrical appliance can be effectively protected, and unpredictable damage caused by simple human error when the electrical appliance is used can be effectively avoided.

4. The self-adaptive control circuit has simple structure and low cost, particularly, a rear-stage circuit such as a frequency conversion device and a motor can keep a uniform design scheme, and has extremely high practical value in engineering.

5. The same product can be used in countries and regions with different voltage grades, so that the model selection during the production of the product is avoided, the selection of the shipment type is not needed any more, and the product storage and sale are greatly facilitated; particularly, the invention has high practical value when the product is exported to countries and regions with different voltage grades, such as America, Japan, and the like.

Drawings

FIG. 1 is a block diagram of an adaptive control circuit for AC power sources of different voltage classes according to the present invention;

FIG. 2 is a block diagram of a later stage load of the adaptive control circuit for the source of AC power of different voltage classes of the present invention;

FIG. 3 is an AC voltage detection circuit of the present invention;

FIG. 4 is a circuit diagram of another AC voltage detection circuit of the present invention;

FIG. 5 is a voltage doubler switch and voltage doubler switch control circuit diagram of the present invention;

FIG. 6 is a circuit diagram of four alternative bidirectional semiconductor switches of the present invention;

FIG. 7 is a logic diagram of the present invention for adaptive control of AC power supply for different voltage levels;

in the figure: the system comprises a 1-single-phase alternating current power supply, a 2-single-phase rectification circuit, a 3-at least two series electrolytic capacitor groups and series electrolytic voltage balance resistor groups, a 4-direct current voltage detection circuit, a 5-alternating current voltage detection circuit, a 6-voltage doubling switch and voltage doubling switch control circuit, a 7-control CPU, an 8-voltage type frequency conversion device and a 9-three-phase motor.

Detailed Description

The invention is further illustrated with reference to the following figures and examples.

The invention provides an alternating current source adaptive control circuit with different voltage grades, which comprises a single-phase alternating current power supply 1, a single-phase rectification circuit 2, at least two series electrolytic capacitor groups and series electrolytic voltage balance resistor groups 3 which form a group, a direct current voltage detection circuit 4, an alternating current voltage detection circuit 5, a voltage doubling switch and voltage doubling switch control circuit 6 and a control CPU7 as shown in figure 1. The dc output P, N of the hardware circuit is directly electrically connected to a dc bus P, N as shown in fig. 2, and the voltage-type inverter device 8 as shown in fig. 2 drives the three-phase motor 9.

In the above hardware circuit, the voltage level of the single-phase ac power supply 1 may be 110V or 220V, respectively. The alternating voltage is rectified by the single-phase rectifying circuit 2 to become direct voltage which is stored in an electrolytic capacitor bank, and the electrolytic capacitor bank consists of two capacitors which are connected in series up and down; according to the magnitude of the load power, the electrolytic capacitor group can be formed by connecting a plurality of groups of electrolytic capacitors in series and then in parallel, for example, four electrolytic capacitors can form two electrolytic capacitor groups which are connected in series and in parallel; the two resistors connected in series play a role in balancing the voltages of the upper electrolytic capacitor and the lower electrolytic capacitor. The dc voltage detection circuit 4 is generally composed of a plurality of resistance voltage-dividing circuits, and obtains a dc voltage signal Vdc, which is input to the control CPU7 to sample the dc voltage by the control CPU 7. The ac voltage detection circuit 5 is composed of an ac transformer and an ac voltage detection circuit, and obtains an ac voltage signal Vac, which is input to the control CPU7 to be used by the control CPU7 to sample an ac voltage. The voltage doubler switch and the voltage doubler switch control circuit 6 are composed of a relay and a relay drive circuit.

The AC voltage detecting circuit 5 is composed of an AC transformer, a rectifying and filtering circuit composed of a diode and a capacitance-resistance device, as shown in fig. 3, a transformer T1 arranged on AC power sources AC-L and AC-N reduces the 220V high voltage AC voltage to about 1.5V, then a rectifying bridge circuit DB2 composed of a diode rectifies and converts it into about 2V dc to be stored in an electrolytic capacitor E5, a resistor R13 plays a discharging role, and finally, a signal is transmitted to an AD port of the control CPU7 through a filtering circuit of the resistor R12 and a capacitor C6, and the control CPU7 can obtain the effective value of the AC voltage in real time through AD sampling conversion. When the input of the AC voltage is 110V, the VAC signal is about half of the input of the 220V high-voltage AC voltage. In fig. 3, since the transformer T1 is used to directly transmit the ac voltage signal, the VAC signal is not affected by whether the voltage doubler switch is turned on or off.

The ac voltage detection circuit 5 may also use a rectifying and smoothing circuit composed of a plurality of resistance voltage-dividing circuits, diodes, and capacitance-resistance devices as shown in fig. 4, and since this circuit does not have a transformer, the cost is further reduced, and the reliability is increased. In fig. 4, a voltage dividing circuit of series resistors R2 and R4 and parallel resistors R6 and R7 is arranged between an AC input terminal AC-L1 and a dc bus N, i.e., GND in the figure, and then rectified by a diode D1 to obtain a dc voltage, which is stored in a capacitor C3, the resistor R8 performs a discharging function, and finally, a filter circuit of the resistor R5 and the capacitor C4 transmits a signal of the figure 115/230 to an AD port of the control CPU7, and the control CPU7 performs AD sampling conversion to obtain an effective value of the AC voltage in real time. However, in the circuit of fig. 4, the 115/230 signal value is related to whether the voltage-doubler switch is closed, and the 115/230 signal value after the voltage-doubler switch is closed is slightly changed from the value when the voltage-doubler switch is not closed. Specifically, in fig. 4, when the effective value of the ac input voltage is 110V, and when the voltage-doubling switch is not closed, the 115/230 signal value is about 0.6V; when the voltage doubling switch is closed, the 115/230 signal rises to about 0.75V. When the effective value of the alternating current input voltage is 220V, and when the voltage doubling switch is not closed, the 115/230 signal value is about 1.2V; when the voltage-doubling switch is closed (the working condition is not allowed to occur during actual operation), the 115/230 signal value rises to about 1.5V. Since the voltage-doubling switching signal is controlled by the control CPU7, the control CPU7 can change the conversion ratio of the signal value of 115/230 to the effective value of the ac voltage in accordance with the voltage-doubling switching signal output by itself. Therefore, the circuit can obtain the accurate value of the actual AC input voltage.

The voltage doubler switch and voltage doubler switch control circuit 6 is composed of a relay and a relay drive circuit, and as shown in fig. 5, the voltage doubler switch control signal VOL _ SW is supplied from the control CPU7, and the control CPU7 outputs the digital voltage doubler switch control signal VOL _ SW by logical operation. When the VOL _ SW signal is high, the transistor Q1 is turned on, two pins CE of the transistor Q1 are short-circuited, the power supply 15V supplies conduction current to the

original pins

1 and 2 of the voltage-multiplying relay RY1 through the resistor R9, so that the voltage-multiplying relay RY1 is attracted, and the pin 5 of the voltage-multiplying relay RY1 is short-circuited with the

pins

3 and 4. At this time, the AC rectifier circuit becomes a voltage doubler rectifier circuit, and the DC bus, which is the DC series voltage of the electrolytic capacitors E1 and E3, is approximately the AC input voltage

And (4) doubling. When the VOL _ SW signal is low, the transistor Q1 is not turned on, so that no current flows in the primary coil of the voltage-doubling relay RY1, the voltage-doubling relay RY1 is open, and the pin 5 of the voltage-doubling relay RY1 is disconnected from the

pins

3 and 4. In this case, the AC rectifier circuit is a normal rectifier circuit, and the DC bus is approximately the AC input voltage

And (4) doubling. Since the voltage doubler switch control signal VOL _ SW is controlled by the control CPU7, and the control CPU7 can use digital filtering, average value calculation, delay count and logic judgment shown in fig. 7 when controlling the voltage doubler switch, the voltage doubler switch and the voltage doubler switch control circuit 6 do not need additional circuits such as complicated delay circuits. Conversely, in order to protect the safety of the entire circuit, the logical judgment operation part of the control CPU7 becomes important.

The relay may also be replaced by four different types of bidirectional semiconductor switching circuits consisting of semiconductor power switching devices of IGBTs or MOSFETs as shown in fig. 6. The bidirectional semiconductor switch circuit of the TYPEA consists of four diodes and an IGBT or an MOSFET, and when the MOSFET is conducted, the circuit is conducted in two directions; when the MOSFET is turned off, the circuit is turned off. The bidirectional semiconductor switch circuit of TYPE B and TYPE C is formed by connecting two IGBT or MOSFET devices in series, and the circuit is switched on when the two IGBT or MOSFET devices are switched on simultaneously and is switched off when the two IGBT or MOSFET devices are switched off simultaneously. The bidirectional semiconductor switch circuit of TYPE D is formed by connecting two MOSFET devices in parallel.

When the ac voltage is input to a single-phase 110V class, the control CPU7 controls the voltage doubling switch to be turned on (relay pull-in) by detecting the ac voltage signal Vac and the dc voltage signal Vdc at that time simultaneously according to the control operation logic shown in fig. 7, and the single-phase rectifier circuit 2, at least two series electrolytic capacitor groups and series electrolytic voltage balancing resistor group 3 forming a group, and the voltage doubling switch and voltage doubling switch control circuit 6 forming a voltage doubling rectifier circuit, at that time, the dc voltage is about the ac voltage

The voltage doubling, that is, after the alternating current of 110V passes through the voltage doubling rectifying circuit, the direct current voltage is about 310V; conversely, when the ac voltage input is of the single-phase 220V class, the control CPU7 controls the voltage-multiplying switch to be turned off (relay to be turned off) by detecting the ac voltage signal Vac and the dc voltage signal Vdc at the same time in accordance with the control operation logic shown in fig. 7, and the single-phase rectifier circuit 2 and the series electrolytic capacitor group and series electrolytic voltage balancing resistor group 3, which are at least two groups, are a normal rectifier circuit in which the dc voltage is approximately the ac voltage at the time

After the double, that is, alternating current 220V passes through the rectifying circuit, the direct current voltage is still about 310V. Thus, if the rear-stage circuit is a frequency conversion device, the frequency conversion device and a motor driven by the frequency conversion device can be designed into an inverter circuit and a motor with 220V alternating current level, and the front-stage input part adopts the alternating current power supply to form an adaptive control circuit, so that the purpose that the same frequency conversion device and the motor automatically adapt to different input alternating current voltage levels is achieved. If the rear-stage circuit is other electric devices, the electric devices can be uniformly designed into a DC 300V grade, and the electric devices can automatically adapt to different input AC voltage gradesThe purpose of (1).

As mentioned above, when the electrical appliance actually works, the user may switch off or on the ac power supply of the electrical appliance at any time; moreover, in areas with poor power grid quality, the alternating current power supply often has large voltage fluctuation; in addition, factors such as the input or disconnection of the load can also cause interference to the electric appliance and the internal circuit; in particular, the ac and dc voltage detection circuits themselves may also be defective. If the voltage-multiplying switch is turned on by mistake under 220V alternating voltage, the direct-current voltage can be as high as more than 600V, and high voltage can break down and damage components in the circuit, thereby causing serious consequences.

In order to ensure the reliability of the electrical appliance, the invention also provides an alternating current source self-adaptive control operation logic method with different voltage levels, as shown in fig. 7, which comprises the following steps:

The central idea of the block diagram shown in fig. 7 is to control the voltage doubling circuit by simultaneously using the information of the two detection circuits, i.e., the ac voltage and the dc voltage, on the premise that the ac and dc sampling voltages are matched with each other. Especially, the proportion calculation and check logic of the alternating voltage and the direct voltage can prevent the power supply voltage fluctuation interference and the electromagnetic noise interference, can prevent the misoperation when a single detection circuit fails from damaging circuits and devices, and ensures the safety of the whole system.

The limitation of the protection scope of the present invention is understood by those skilled in the art, and various modifications or changes which can be made by those skilled in the art without inventive efforts based on the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. The alternating current source adaptive control circuit with different voltage grades is characterized by comprising a single-phase alternating current power supply (1), a single-phase rectification circuit (2), at least two series electrolytic capacitor sets and series electrolytic voltage balance resistor sets (3) which form a set, a direct current voltage detection circuit (4), an alternating current voltage detection circuit (5), a voltage doubling switch and voltage doubling switch control circuit (6) and a control CPU (7), wherein the alternating current voltage grade of the single-phase alternating current power supply (1) is 110V or 220V, the alternating current voltage of the single-phase alternating current power supply (1) is rectified by the single-phase rectification circuit (2) to become direct current voltage to be stored in the electrolytic capacitor sets, the direct current voltage detection circuit (4) inputs a detected direct current voltage signal Vdc into the control CPU (7) to enable the control CPU (7) to sample the direct current voltage, the alternating voltage detection circuit (5) inputs the detected alternating voltage signal Vac to the control CPU (7) and the control CPU (7) samples the alternating voltage, and the voltage doubler switch control circuit (6) are controlled by a control signal of the control CPU (7).

2. Alternating current source adaptation control circuit for different voltage classes according to claim 1, characterized in that the single-phase rectification circuit (2) is constituted by a rectification bridge.

3. Alternating current source adaptive control circuit of different voltage classes according to claim 1, characterized in that the direct voltage detection circuit (4) is constituted by a plurality of resistive voltage division circuits.

4. Alternating current source adaptive control circuit according to claim 1, characterized in that the alternating voltage detection circuit (5) is composed of an alternating current transformer and a rectifying and filtering circuit composed of diodes and capacitance-resistance devices.

5. Alternating current source adaptive control circuit of different voltage classes according to claim 1, characterized in that the alternating voltage detection circuit (5) is composed of a plurality of resistive voltage division circuits and a rectifying and filtering circuit composed of diodes and resistive-capacitive devices.

6. Alternating current power supply adaptive control circuit of different voltage classes according to claim 1, characterized in that the voltage-doubler switch and voltage-doubler switch control circuit (6) is composed of a relay and a relay drive circuit.

7. Alternating current power supply adaptive control circuit of different voltage levels according to claim 1, characterized in that the voltage-doubling switch and voltage-doubling switch control circuit (6) is composed of a bidirectional semiconductor switch circuit composed of semiconductor switch devices of IGBT or MOSFET and a drive circuit.

8. The method for adaptively controlling the operation logic of the alternating current sources with different voltage levels is characterized by comprising the following steps of: