CN109624744B - Modular charger and safety control method thereof - Google Patents

Abstract

The invention discloses a modular charger and a safety control method thereof, relates to the technical field of modular power supply equipment, and aims to solve the problem of poor safety of the conventional modular charger. The technical scheme is that the power supply device comprises a power supply module, wherein the power supply module comprises an AC-DC power supply unit, a front end protection unit, a rear end output unit, a rear end signal acquisition unit and a control unit; the control unit is connected with a first intermediate relay and a second intermediate relay, and can control the first intermediate relay and the second intermediate relay to operate according to current signals collected by the rear-end signal collection unit, so that input and output of the charger are cut off. Has the advantages of small size and good safety.

Description

Modular charger and safety control method thereof

Technical Field

The invention relates to the technical field of module power supply equipment, in particular to a modular charger and a safety control method thereof.

Background

The modular charger is a special device for charging the vehicle battery of the electric vehicle or other electric vehicles, is a power conversion device with specific functions used for charging the battery, and a power supply module in the power conversion device has the advantages of small size, high power and the like. The power module is shaped like a brick, so the power module is called a brick power supply. At present, the brick power supply can be divided into a full brick power supply module, a half brick power supply module, a quarter power supply module, an eighth power supply module and the like according to the size of the brick power supply. Taking a full-brick power supply as an example, the full-brick power supply is a standard module power supply with a full-brick size, and the power supply can effectively utilize space and is often used for a power supply module of a vehicle-mounted charger.

In the prior art, when the charger is assembled, an upper cover and a lower cover are closed to form a cavity, the PCB is installed in the cavity, pouring sealant is introduced into the cavity from a through hole of the upper cover, and the pouring sealant flows in the cavity to cover the PCB, so that the effects of water resistance and vibration resistance are achieved, and the charger is suitable for being used in severe environments.

Also disclosed in chinese patent application No. 201420439488 is an AC-DC full-brick power module, which includes an aluminum substrate and a small capacitor plate, where the aluminum substrate has a rectifier bridge D6, D7, an inductor L2, a sampling resistor R7, a MOS transistor Q8, a rectifier transistor D9, a thyristor SCR1, an LLC resonant inductor L1, an LLC half-bridge MOS transistor Q1, a transistor Q2, an isolation transformer T1, a secondary side synchronous rectification MOS transistor, an output sampling resistor R23, and an output filter capacitor; LLC resonance capacitors are distributed on the small capacitor plates; the distribution layout of the main components is that rectifier bridges D6 and D7 are located at the upper left corner of the aluminum substrate, an inductor L2 is located at the lower left corner of the aluminum substrate, LLC half-bridge MOS tubes Q1 and Q2 are located at the middle lower part of the aluminum substrate, and output filter capacitors are vertically arranged at the edge of the right side of the aluminum substrate, so that the power which can be output by a power supply, the overall efficiency and the reliability are optimal.

However, the above prior art solutions have the following drawbacks: when a charger adopting the AC-DC full-brick power module is used in a harsh environment (such as under the conditions of high temperature, thunderstorm weather and the like), the service life of a charged load is affected due to unstable output current, and even safety accidents such as load explosion and the like can occur in severe cases, so that the safety is poor.

Disclosure of Invention

The invention aims to provide a modular charger and a safety control method thereof, which have the advantages of small size and good safety.

The above object of the present invention is achieved by the following technical solutions:

a modular charger, includes power module, power module includes:

an AC-DC power supply unit; a front end protection unit provided at an input terminal of the AC-DC power supply unit; a back-end output unit provided at an output end of the AC-DC power supply unit; the rear end signal acquisition unit is arranged between the rear end output unit and the load and is used for acquiring an output current signal of the rear end output unit; the control unit is connected with the rear end signal acquisition unit and is used for cutting off the input and the output of the charger according to the current signal acquired by the rear end signal acquisition unit;

the control unit is connected with a first intermediate relay and a second intermediate relay, the first intermediate relay comprises a first normally closed contact and a second normally closed contact, and the second intermediate relay comprises a third normally closed contact and a fourth normally closed contact; the first normally closed contact is connected in series with a line connected with the live wire and the front end protection unit, and the second normally closed contact is connected in series with a line connected with the zero wire and the front end protection unit; the third normally closed contact is connected in series on a line connecting the positive output end of the rear-end signal acquisition unit with the load, and the fourth normally closed contact is connected in series on a line connecting the negative output end of the rear-end signal acquisition unit with the load.

By adopting the technical scheme, the power module of the charger adopts a modular design, so that the charger has the advantage of small volume. When the charger is used in a harsh environment (such as high temperature and thunderstorm weather), the output current of the charger is unstable, which easily causes damage to the load or safety accidents such as explosion, so the output end of the rear-end output unit is provided with the rear-end signal acquisition unit, when the acquired current signal (namely the output current signal/input current signal of the load of the charger) is abnormal, the control unit can control the first intermediate relay and the second intermediate relay to operate, thereby the input and output of the charger are cut off, the safety accidents are effectively avoided, and the charger also has the good safety effect on the basis of small size.

The invention is further configured to: the front-end protection unit comprises a fuse, a thermistor, a piezoresistor, a common-mode inductor, a first capacitor, a second capacitor and a third capacitor, wherein the first capacitor, the second capacitor and the third capacitor are nonpolar capacitors, and the common-mode inductor comprises a first inductance coil and a second inductance coil; one end of the fuse is connected with one end of the first normally closed contact connected with the front-end input unit, and the other end of the fuse is connected with one end of the thermistor; the other end of the thermistor is connected with one end of the piezoresistor, one pole of the first capacitor and one end of the first inductance coil of the common-mode inductor, and the other end of the piezoresistor and the other pole of the first capacitor are connected with one end of the second normally-closed contact, which is connected with the front-end input unit, and one end of the second inductance coil of the common-mode inductor; the other end of the first inductance coil of the common-mode inductor is connected with one pole of the second capacitor and the live wire end of the AC-DC power supply unit, and the other end of the second inductance coil of the common-mode inductor is connected with one pole of the third capacitor and the null wire end of the AC-DC power supply unit; and the other pole of the second capacitor and the other pole of the third capacitor are both connected with the ground wire and the ground wire terminal of the AC-DC power supply unit.

The invention is further configured to: the rear-end output unit comprises a fourth capacitor, a fifth capacitor and a transient suppressor, wherein the fourth capacitor is a polar capacitor, and the fifth capacitor is a non-polar capacitor; the positive electrode of the fourth capacitor, one electrode of the fifth capacitor and one end of the transient suppressor are connected with the positive electrode output end of the AC-DC power supply unit and one end of the third normally-closed contact connected with the rear-end output unit, and the negative electrode of the fourth capacitor, the other electrode of the fifth capacitor and the other end of the transient suppressor are connected with the negative electrode output end of the AC-DC power supply unit and one end of the fourth normally-closed contact connected with the rear-end output unit.

By adopting the technical scheme, the input and output stability of the charger is further ensured through the front-end protection module and the rear-end output module, so that the performance and the safety of the charger are further improved.

The invention is further configured to: the rear end signal acquisition unit comprises a voltage sensor for detecting load input voltage and a current sensor for detecting load input current, wherein the voltage sensor and the current sensor are both connected with a signal conditioning unit, and the signal conditioning unit is connected to the control unit.

By adopting the technical scheme, the signal conditioning unit has the functions of signal amplification, isolation and signal filtering, and can stably transmit signals detected by the voltage sensor and the current sensor to the control unit.

The invention is further configured to: the control unit comprises an A/D converter and a controller, the output end of the signal conditioning unit is connected to the input end of the A/D converter, the output end of the A/D converter is connected to the input end of the controller, and the output end of the controller is connected with a coil of the first intermediate relay and a coil of the second intermediate relay.

By adopting the technical scheme, the A/D converter is used for converting the detected voltage or current signal (analog quantity) into equivalent digital quantity which can be identified by the controller.

The invention is further configured to: the control unit is also connected with a wireless transceiver, and the wireless transceiver is used for the mobile terminal to send a control signal for cutting off the input and the output of the charger to the control unit.

By adopting the technical scheme, under certain severe environments (such as thunderstorm weather, insolation weather and the like), when the input and the output of the charger are not cut off, in order to ensure the personal safety of a user, the user does not need to contact the charger, and the input and the output of the charger can be cut off actively by sending a control signal for cutting off the input and the output of the charger to the control unit through the mobile terminal.

The second aim of the invention is realized by the following technical scheme:

a safety control method of a modular charger comprises the following steps:

the control unit is configured for cutting off the input and the output of the charger;

a signal acquisition unit at the rear end of a branch circuit for connecting a load is configured to acquire the waveform of load input current in real time, and electrical parameters at least containing the magnitude of the load input current are extracted;

generating an ideal input current waveform of a load according to a rated output current i of a charger;

presetting a plurality of continuous detection periods, wherein each detection period comprises a plurality of continuous sub-periods;

comparing the acquired load input current waveform with the ideal input current waveform of the load to obtain a matching parameter M in the sub-period, and generating a matching factor value X1 according to the matching parameter M;

calculating a quantity parameter N of the inrush current signal in the sub-period according to the extracted electrical parameter of the magnitude of the load input current, and generating a signal factor value X2 according to the quantity parameter N;

obtaining a judgment score X, X = (X1f1+ X2f2)/2 by weighted averaging of the matching factor value X1 and the signal factor value X2 in the same sub-period, wherein f1 is the weight of X1, and f2 is the weight of X2;

if the number of the sub-periods with the judgment value X larger than the preset value in one detection period is larger than the preset value, the control unit cuts off the input and the output of the charger;

if the sub-period values of which the judgment score X is larger than the preset score are smaller than or equal to the preset values in one detection period, the control unit does not cut off the input and the output of the charger.

By adopting the technical scheme, the input current signal of the load can be detected in real time, when the input current signal of the load is abnormal, the control unit can perform corresponding actions to cut off the input and the output of the charger, and the safety of the charger is effectively ensured.

The invention is further configured to: the ideal input current waveform is preset to contain C sudden-change current signals in a sub-period, wherein the matching factor value X1=1/M and the signal factor value X2= N/C.

The invention is further configured to: the calculation method of the matching parameter M comprises the following steps: calculating the area S1 enclosed by the part of the ideal input current waveform of the load in the sub-period, which is positioned above the current i straight line, and the current i straight line; calculating the area S2 enclosed by the part of the load input current waveform above the current i straight line and the current i straight line in the sub-period; calculating the area S3 enclosed by the part of the ideal input current waveform of the load in the sub-period, which is positioned below the current i straight line, and the current i straight line; calculating the area S4 enclosed by the part of the load input current waveform under the current i straight line and the current i straight line in the sub-period; matching parameter M = (S1/S2+ S3/S4)/2.

The invention is further configured to: the calculation method of the matching parameter M comprises the following steps: acquiring a current maximum value i1 of a part, above a current i straight line, of an ideal input current waveform of a load in a sub-period; acquiring a current maximum value i2 of a part of a load input current waveform above a current i straight line in the sub-period; acquiring a current minimum value i3 of a part of an ideal input current waveform of the load in the sub-period, which is positioned below a current i straight line; acquiring a current minimum value i4 of a part of a load input current waveform positioned below a current i straight line in the sub-period; matching parameter M = (i1/i2+ i4/i 3)/2.

By adopting the technical scheme, whether the input and the output of the charger are cut off is judged from the judgment score X and the preset numerical value, the judgment score X is calculated by the matching factor X1 and the signal factor X2, and the current fluctuation (namely the area enclosed by the part of the load input current waveform which is larger than or smaller than the rated current i of the charger in the sub-period and the current which is the i straight line) and the stability of the current direction (namely the number of the mutation signals of the load input current waveform in the sub-period) of the direct current output by the charger are fully considered from two angles, the abnormal output condition of the charger can be quickly found in one detection period, so that the input and the output of the charger are quickly cut off, the occurrence of safety accidents such as load damage or explosion is avoided, and the invention has better safety.

In conclusion, the beneficial technical effects of the invention are as follows:

1. through the arrangement of the front-end protection unit, the rear-end output unit, the rear-end signal acquisition unit and the control unit, the charger has the advantage of good safety on the basis of small size;

2. through the arrangement of the signal conditioning unit and the A/D converter, the effect of stably transmitting the acquired signals to the controller is achieved;

3. the wireless transceiver is provided, which can further improve the security.

Drawings

Fig. 1 is a block diagram of a modular charger according to a first embodiment of the present invention;

FIG. 2 is a schematic circuit diagram of a front-end input unit according to an embodiment of the present invention;

fig. 3 is a schematic circuit diagram of a back-end output unit, a back-end signal acquisition unit and a control unit according to an embodiment of the present invention;

FIG. 4 is a waveform diagram illustrating ideal input current and load input current according to an embodiment of the present invention;

FIG. 5 is a waveform diagram illustrating an ideal input current and a load input current according to a second embodiment of the present invention;

fig. 6 is a schematic diagram showing a connection relationship between a mobile terminal and a control unit according to a third embodiment of the present invention.

In the figure, 10, a front end protection unit; 20. an AC-DC power supply unit; 30. a back-end output unit; 40. a load; 50. a back end signal acquisition unit; 51. a voltage sensor; 52. a current sensor; 53. a signal conditioning unit; 60. a control unit; 61. an A/D converter; 62. a controller; 63. a wireless transceiver; 70. a first intermediate relay; 80. a second intermediate relay; 90. a mobile terminal.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Example one

Referring to fig. 1, the modular charger disclosed by the present invention includes a power module, where the power module includes an AC-DC power unit 20, a front-end protection unit 10, a rear-end output unit 30, a rear-end signal acquisition unit 50, and a control unit 60. The control unit 60 is connected to the first intermediate relay 70 and the second intermediate relay 80, and the control unit 60 can control the first intermediate relay 70 and the second intermediate relay 80 to operate according to the current signal collected by the rear end signal collection unit 50, so as to cut off the input and output of the charger, and control the first intermediate relay 70 and the second intermediate relay 80 to reset when the charger is restarted.

Referring to fig. 1 and 2, the first intermediate relay 70 includes a first normally closed contact KA1-1 and a second normally closed contact KA1-2, the front end protection unit 10 includes a FUSE, a common mode inductor T1, a first capacitor C1, a second capacitor C2, a third capacitor C3, a thermistor NTC and a varistor RV, the first capacitor C1, the second capacitor C2 and the third capacitor C3 are all nonpolar capacitors, the FUSE is a slow-melting type ZY0JGB12D 25W module, and the common mode inductor T1 includes a first inductor coil and a second inductor coil. One end of the first normally closed contact KA1-1 is used for connecting with the live wire L, and the other end of the first normally closed contact KA1-1 is connected with one end of the FUSE FUSE. The other end of the FUSE is connected with the live wire L, and the other end of the FUSE is connected with one end of the thermistor NTC. The other end of the thermistor NTC is connected with one end of a piezoresistor RV, one pole of a first capacitor C1 and one end of a first inductance coil of a common-mode inductor T1, the other end of the piezoresistor RV, the other pole of the first capacitor C1 and one end of a second inductance coil of the common-mode inductor T1 are connected with one end of a second normally-closed contact KA1-2, and the other end of the second normally-closed contact KA1-2 is used for being connected with a zero line N. The other end of the first inductor of the common mode inductor T1 is connected to one pole of the second capacitor C2 and the live wire end of the AC-DC power supply unit 20, and the other end of the second inductor of the common mode inductor T1 is connected to one pole of the third capacitor C3 and the neutral wire end of the AC-DC power supply unit 20. The other pole of the second capacitor C2 and the other pole of the third capacitor C3 are both connected to the ground line FG and the ground terminal of the AC-DC power supply unit 20.

Referring to fig. 1 and 3, the second intermediate relay 80 includes a third normally-closed contact KA2-1 and a fourth normally-closed contact KA2-2, the back end output unit 30 includes a fourth capacitor C4, a fifth capacitor C5, and a transient suppressor TVS, the fourth capacitor C4 is a polar capacitor, and the fifth capacitor C5 is a non-polar capacitor. An anode of the fourth capacitor C4, a pole of the fifth capacitor C5 and one end of the transient suppressor TVS are connected to the positive output terminal of the AC-DC power supply unit 20 and one end of the third normally-closed contact KA2-1, and the other end of the third normally-closed contact KA2-1 is used for being connected to the positive input terminal of the load 40. The cathode of the fourth capacitor C4, the other pole of the fifth capacitor C5 and the other end of the transient suppressor TVS are all connected to the negative output terminal of the AC-DC power supply unit 20 and one end of a fourth normally-closed contact KA2-2, and the other end of the fourth normally-closed contact KA2-2 is used for being connected to the negative input terminal of the load 40.

Referring to fig. 1 and 3, the control unit 60 includes an a/D converter 61 and a controller 62, and the back-end signal collection unit 50 includes a voltage sensor 51 and a current sensor 52. The voltage sensor 51 is connected in parallel between the positive output terminal of the AC-DC power supply unit 20 and the negative output terminal of the AC-DC power supply unit 20, and detects an input voltage of the load 40. The current sensor 52 is connected in series to a line connecting the negative output terminal of the AC-DC power supply unit 20 and the fourth normally-closed contact KA2-2, and is configured to detect the input current of the load 40. The voltage sensor 51 and the current sensor 52 are both connected with a signal conditioning unit 53, the signal conditioning unit 53 is connected to the input end of the a/D converter 61 through an RS485 bus, the output end of the a/D converter 61 is connected to the input end of the controller 62, and the output end of the controller 62 is connected with the coil of the first intermediate relay 70 and the coil of the second intermediate relay 80. Signals collected by the voltage sensor 51 and the current sensor 52 pass through the corresponding signal conditioning units 53 and are transmitted to the controller 62 through the RS485 bus and the A/D converter 61, and the controller 62 receives the signals to form a load input current waveform and extract electrical parameters at least including the magnitude of the load input current. An ideal input current waveform of the load 40 is generated according to the rated output current i of the charger, and in consideration of the actual use condition, a periodic abrupt change signal is arranged on the ideal input current waveform, so that the load input current waveform is compared with the ideal input current waveform.

Referring to fig. 4, a partial schematic diagram of an ideal input current waveform and a load input current waveform is shown from top to bottom. In the present embodiment, a plurality of successive detection periods T1, T2 … … Tn for comparing the ideal input current waveform and the load input current waveform are provided, each detection period including successive sub-periods T1 and T2. And obtaining a matching parameter M by comparing the ideal input current waveform with the load input current waveform in the sub-period, and generating a matching factor value X1=1/M according to the matching parameter M. Specifically, taking sub-period T1 of detection period T1 as an example, area S1 surrounded by a straight line with current i and a portion of the ideal input current waveform located above the straight line with current i in sub-period T1 is calculated, area S2 surrounded by a straight line with current i and a portion of the load input current waveform located above the straight line with current i in sub-period T1 is calculated, area S3 surrounded by a straight line with current i and a portion of the ideal input current waveform located below the straight line with current i in sub-period T1 is calculated, area S4 surrounded by a straight line with current i and a portion of the load input current waveform located below the straight line with current i in sub-period T1 is calculated, and matching parameter M = (S1/S2+ S3/S4)/2 is obtained, and matching factor value X1= 1/M.

It should be noted that the present embodiment is exemplified by the ideal input current waveform and the load input current waveform in the sub-period T1 of the detection period T1 each having only one abrupt change signal larger than i and one abrupt change signal smaller than i, and those skilled in the art can understand that, when the detection period T1 has more than 2 sudden change signals in the sub-period T1, S1 is the sum of the portion of the ideal input current waveform above the current i straight line and the area enclosed by the current i straight line in the sub-period T1, s2 is the sum of the area enclosed by the part of the load input current waveform located above the current i straight line and the current i straight line in the sub-period t1, s3 is the sum of the area enclosed by the part of the ideal input current waveform under the current i straight line and the current i straight line in the sub-period t1, s4 is the sum of the area enclosed by the portion of the load input current waveform located below the current i straight line and the current i straight line in the sub-period t 1.

Taking the sub-period T1 of the detection period T1 as an example, the number parameter N of the inrush current signal of the load input current waveform in the sub-period T1 is calculated, it is preset that the ideal input current waveform in the sub-period T1 includes 2 inrush current signals, and the signal factor value X2= N/2 is obtained according to the number parameter N. For example, in fig. 4, if the parameter N =2 of the number of the inrush current signal in the sub-period T1 of the detection period T1 of the load input current waveform, the signal factor value X2=2/2= 1.

Finally, the matching factor value X1 and the signal factor value X2 in the same sub-period are weighted and averaged to obtain the judgment score X, X = (X1f1+ X2f2)/2, wherein f1 is the weight of X1, and f2 is the weight of X2. The control unit 60 determines whether to control the first intermediate relay 70 and the second intermediate relay 80 to operate to cut off the input and output of the charger by determining whether the number of the sub-periods in which the score X is greater than the preset score is greater than the preset number in one detection period. Specifically, if f1= f2=0.5, the preset score is 2, and the preset numerical value is 1; when the number of the sub-periods with the score X larger than 2 is larger than 1 within one detection period, the control unit 60 controls the first intermediate relay 70 and the second intermediate relay 80 to operate to cut off the input and the output of the charger; when the number of sub-periods in which the score X is greater than 2 in one detection period is less than or equal to 1, the control unit 60 does not control the first intermediate relay 70 and the second intermediate relay 80 to operate.

In the embodiment, whether the input and the output of the charger are cut off is judged from the judgment score value X and the preset numerical value, the judgment score value X is calculated from the matching factor value X1 and the signal factor value X2, and the current fluctuation (namely the area formed by the part of the load input current waveform which is greater than or less than the rated current i of the charger in the sub-period and the current which is a straight line) of the direct current output by the charger and the stability of the current direction (namely the number of the mutation signals of the load input current waveform in the sub-period) are fully considered from two angles, so that the output abnormal condition of the charger can be quickly found in one detection period, the input and the output of the charger are quickly cut off, the safety accidents such as the damage or the explosion of the load 40 are avoided, and the safety is good.

Example two

Referring to fig. 5, the difference between the present embodiment and the first embodiment is that the method for calculating the matching parameter M includes: taking sub-period T1 of detection period T1 as an example, a current maximum value i1 of a portion of sub-period T1 where the ideal input current waveform is located above the current i straight line, a current maximum value i2 of a portion of the sub-period where the load input current waveform is located above the current i straight line, a current minimum value i3 of a portion of the sub-period where the ideal input current waveform is located below the current i straight line, and a current minimum value i4 of a portion of the sub-period where the load input current waveform is located below the current i straight line are obtained. The more the matching parameter M = (i1/i2+ i4/i3)/2, i2 approaches i1 and i4 approaches i3, the more the matching parameter M approaches 1 and the more the matching factor value X1 approaches 1.

EXAMPLE III

Referring to fig. 6, the difference between the present embodiment and the first embodiment is: the control unit 60 is further connected to a wireless transceiver 63, and the mobile terminal 90 can be communicatively linked with the control unit 60 through the wireless transceiver 63. In some severe environments (such as thunderstorm weather, insolation weather, etc.), when the input and output of the charger are not cut off, in order to ensure the personal safety of the user, the user does not need to contact the charger, and a control signal for cutting off the input and output of the charger is sent to the control unit 60 through the mobile terminal 90, namely, the input and output of the charger are cut off actively.

Example four

A safety control method of a modular charger, referring to fig. 1 and 4, includes:

the control unit 60 for cutting off the input and output of the charger is configured, the control unit 60 cuts off the input and output of the charger by controlling the operation of the first intermediate relay 70 and the second intermediate relay 80, and it should be noted that when the charger is re-started, the control unit 60 controls the first intermediate relay 70 and the second intermediate relay 80 to be reset.

The back end signal acquisition unit 50 is configured to acquire a load input current waveform in real time through a branch for connecting the load 40, and extract an electrical parameter at least including the magnitude of the load input current, and the back end signal acquisition unit 50 is connected with the control unit 60 through an RS485 bus.

An ideal input current waveform of the load 40 is generated according to the rated output current i of the charger, and specifically, a periodic abrupt change signal is set on the ideal input current waveform in consideration of the actual use condition of the charger.

A plurality of successive sensing periods T1, T2 … … Tn for comparing the ideal input current waveform with the load input current waveform are preset, each sensing period comprising successive sub-periods T1 and T2.

And comparing the acquired load input current waveform with the ideal input current waveform of the load 40 to obtain a matching parameter M in the sub-period, and generating a matching factor value X1 according to the matching parameter M, wherein X1= 1/M.

Specifically, taking the sub-period T1 of the detection period T1 as an example, the current maximum value i1 of the portion of the sub-period T1 where the ideal input current waveform of the load 40 is located above the current i straight line, the current maximum value i2 of the portion of the sub-period where the ideal input current waveform of the load 40 is located above the current i straight line, the current minimum value i3 of the portion of the sub-period where the ideal input current waveform of the load 40 is located below the current i straight line, and the current minimum value i4 of the portion of the sub-period where the ideal input current waveform of the load is located below the current i straight line are obtained. The more the matching parameter M = (i1/i2+ i4/i3)/2, i2 approaches i1 and i4 approaches i3, the more the matching parameter M approaches 1 and the more the matching factor value X1 approaches 1.

And calculating a quantity parameter N of the abrupt current signals in the sub-period according to the extracted electrical parameter of the magnitude of the load input current, and generating a signal factor value X2 according to the quantity parameter N, wherein the signal factor value X2= N/C if the ideal input current waveform is preset to contain C abrupt current signals in one sub-period.

Specifically, taking the sub-period T1 of the detection period T1 as an example, the number parameter N of the inrush current signal of the load input current waveform in the sub-period T1 is calculated, it is preset that the ideal input current waveform in the sub-period T1 includes 2 inrush current signals, and the signal factor value X2= N/2 is obtained according to the number parameter N. For example, in fig. 4, if the parameter N =2 of the number of the inrush current signal in the sub-period T1 of the detection period T1 of the load input current waveform, the signal factor value X2=2/2= 1.

Obtaining a judgment score X, X = (X1f1+ X2f2)/2 by weighted averaging of the matching factor value X1 and the signal factor value X2 in the same sub-period, wherein f1 is the weight of X1, and f2 is the weight of X2; the control unit 60 determines whether to control the first intermediate relay 70 and the second intermediate relay 80 to operate to cut off the input and output of the charger by determining whether the number of the sub-periods in which the score X is greater than the preset score is greater than the preset number in one detection period.

Specifically, if f1= f2=0.5, the preset score is 2, and the preset numerical value is 1; when the number of the sub-periods with the score X larger than 2 is larger than 1 within one detection period, the control unit 60 controls the first intermediate relay 70 and the second intermediate relay 80 to operate to cut off the input and the output of the charger; when the number of sub-periods in which the score X is greater than 2 in one detection period is less than or equal to 1, the control unit 60 does not control the first intermediate relay 70 and the second intermediate relay 80 to operate.

EXAMPLE five

Referring to fig. 5, the difference between this embodiment and the fourth embodiment is that the method for calculating the matching parameter M includes: taking a sub-period T1 of the detection period T1 as an example, an area S1 surrounded by a portion of the ideal input current waveform above the current i straight line in the sub-period T1 and the current i straight line is calculated, an area S2 surrounded by a portion of the load input current waveform above the current i straight line in the sub-period T1 and the current i straight line is calculated, an area S3 surrounded by a portion of the ideal input current waveform below the current i straight line in the sub-period T1 and the current i straight line is calculated, an area S4 surrounded by a portion of the load input current waveform below the current i straight line in the sub-period T1 and the current i straight line is calculated, and a matching parameter M = (S1/S2+ S3/S4)/2 is obtained.

It should be noted that the present embodiment is exemplified by the ideal input current waveform and the load input current waveform in the sub-period T1 of the detection period T1 each having only one abrupt change signal larger than i and one abrupt change signal smaller than i, however, it can be understood by those skilled in the art that when the detection period T1 has more than 2 mutation signals in the sub-period T1, s1 is the sum of the area enclosed by the part of the ideal input current waveform above the current i straight line and the current i straight line in the sub-period t1, s2 is the sum of the area enclosed by the part of the load input current waveform located above the current i straight line and the current i straight line in the sub-period t1, s3 is the sum of the area enclosed by the part of the ideal input current waveform under the current i straight line and the current i straight line in the sub-period t1, s4 is the sum of the area enclosed by the portion of the load input current waveform located below the current i straight line and the current i straight line in the sub-period t 1.

EXAMPLE six

Referring to fig. 6, the present embodiment is different from the fourth embodiment in that the present embodiment further includes: a wireless transceiver 63 is configured for the control unit 60, and the control unit 60 and the wireless transceiver 63 form a bidirectional communication connection; the mobile terminal 90 can establish a communication link with the control unit 60 through the wireless transceiver 63, so that the user can select whether to send a control signal for cutting off the input and output of the charger to the control unit 60 through the mobile terminal 90.

The embodiments of the present invention are preferred embodiments of the present invention, and the scope of the present invention is not limited by these embodiments, so: all equivalent changes made according to the structure, shape and principle of the invention are covered by the protection scope of the invention.

Claims (3)

1. The utility model provides a modularization machine that charges, includes power module, its characterized in that, power module includes:

an AC-DC power supply unit (20); a front end protection unit (10) provided at an input terminal of the AC-DC power supply unit (20); a back-end output unit (30) provided at an output end of the AC-DC power supply unit (20); the rear end signal acquisition unit (50) is arranged between the rear end output unit (30) and the load (40) and is used for acquiring an output current signal of the rear end output unit (30); the control unit (60) is connected with the rear end signal acquisition unit (50) and is used for cutting off the input and the output of the charger according to the current signal acquired by the rear end signal acquisition unit (50);

wherein the control unit (60) is connected with a first intermediate relay (70) and a second intermediate relay (80), the first intermediate relay (70) comprises a first normally closed contact and a second normally closed contact, and the second intermediate relay (80) comprises a third normally closed contact and a fourth normally closed contact; the first normally closed contact is connected in series with a line connected with the live wire and the front end protection unit (10), and the second normally closed contact is connected in series with a line connected with the zero wire and the front end protection unit (10); the third normally closed contact is connected in series on a line connecting the positive output end of the rear-end signal acquisition unit (50) with the load (40), and the fourth normally closed contact is connected in series on a line connecting the negative output end of the rear-end signal acquisition unit (50) with the load (40);

the front-end protection unit (10) comprises a fuse, a thermistor, a piezoresistor, a common-mode inductor, a first capacitor, a second capacitor and a third capacitor, wherein the first capacitor, the second capacitor and the third capacitor are nonpolar capacitors, and the common-mode inductor comprises a first inductance coil and a second inductance coil; one end of the fuse is connected with one end of the first normally closed contact connected with the front-end input unit, and the other end of the fuse is connected with one end of the thermistor; the other end of the thermistor is connected with one end of the piezoresistor, one pole of the first capacitor and one end of the first inductance coil of the common-mode inductor, and the other end of the piezoresistor and the other pole of the first capacitor are connected with one end of the second normally-closed contact, which is connected with the front-end input unit, and one end of the second inductance coil of the common-mode inductor; the other end of the first inductance coil of the common-mode inductor is connected with one pole of the second capacitor and the live wire end of the AC-DC power supply unit (20), and the other end of the second inductance coil of the common-mode inductor is connected with one pole of the third capacitor and the live wire end of the AC-DC power supply unit (20); the other pole of the second capacitor and the other pole of the third capacitor are both connected with the ground wire and the ground wire end of the AC-DC power supply unit (20);

the rear-end output unit (30) comprises a fourth capacitor, a fifth capacitor and a transient suppressor, wherein the fourth capacitor is a polar capacitor, and the fifth capacitor is a non-polar capacitor; the anode of the fourth capacitor, one pole of the fifth capacitor and one end of the transient suppressor are connected with the anode output end of the AC-DC power supply unit (20) and one end of the third normally-closed contact connected with the rear-end output unit (30), and the cathode of the fourth capacitor, the other pole of the fifth capacitor and the other end of the transient suppressor are connected with the cathode output end of the AC-DC power supply unit (20) and one end of the fourth normally-closed contact connected with the rear-end output unit (30);

the rear-end signal acquisition unit (50) comprises a voltage sensor (51) for detecting the input voltage of the load (40) and a current sensor (52) for detecting the input current of the load (40), the voltage sensor (51) and the current sensor (52) are both connected with a signal conditioning unit (53), and the signal conditioning unit (53) is both connected to a control unit (60);

the control unit (60) comprises an A/D converter (61) and a controller (62), the output end of the signal conditioning unit (53) is connected to the input end of the A/D converter (61), the output end of the A/D converter (61) is connected to the input end of the controller (62), and the output end of the controller (62) is connected with a coil of the first intermediate relay (70) and a coil of the second intermediate relay (80);

signals collected by the voltage sensor (51) and the current sensor (52) pass through the corresponding signal conditioning unit (53) and are transmitted to the controller (62) through the RS485 bus and the A/D converter (61), and the controller (62) receives the signals, forms a load input current waveform and extracts electrical parameters at least containing the magnitude of the load input current; the controller (62) is specifically configured to: generating an ideal input current waveform of a load (40) according to a rated output current i of a charger; presetting a plurality of continuous detection periods, wherein each detection period comprises a plurality of continuous sub-periods; comparing the acquired load input current waveform with an ideal input current waveform of a load (40) to obtain a matching parameter M in the sub-period, and generating a matching factor value X1 according to the matching parameter M; calculating a quantity parameter N of the inrush current signal in the sub-period according to the extracted electrical parameter of the magnitude of the load input current, and generating a signal factor value X2 according to the quantity parameter N; obtaining a judgment score X, X = (X1f1+ X2f2)/2 by weighted averaging of the matching factor value X1 and the signal factor value X2 in the same sub-period, wherein f1 is the weight of X1, and f2 is the weight of X2; if the number of the sub-periods with the judgment value X larger than the preset value in one detection period is larger than the preset value, the control unit (60) cuts off the input and the output of the charger; if the sub-period values of which the score X is larger than the preset score are smaller than or equal to the preset value in the detection period, the control unit (60) does not cut off the input and the output of the charger;

the ideal input current waveform comprises C sudden-change current signals in a sub-period, wherein the matching factor value X1=1/M and the signal factor value X2= N/C; the calculation method of the matching parameter M comprises the following steps:

calculating an area S1 enclosed by a part of an ideal input current waveform of the load (40) above a current i straight line and the current i straight line in the sub-period; calculating the area S2 enclosed by the part of the load input current waveform above the current i straight line and the current i straight line in the sub-period; calculating an area S3 enclosed by a part of an ideal input current waveform of the load (40) positioned below a current i straight line and the current i straight line in the sub-period; calculating the area S4 enclosed by the part of the load input current waveform under the current i straight line and the current i straight line in the sub-period; matching parameter M = (S1/S2+ S3/S4)/2;

alternatively, the first and second electrodes may be,

acquiring a current maximum value i1 of a part, above a current i straight line, of an ideal input current waveform of the load (40) in the sub-period; acquiring a current maximum value i2 of a part of a load input current waveform above a current i straight line in the sub-period; acquiring a current minimum value i3 of a part, below a current i straight line, of an ideal input current waveform of the load (40) in the sub-period; acquiring a current minimum value i4 of a part of a load input current waveform positioned below a current i straight line in the sub-period; matching parameter M = (i1/i2+ i4/i 3)/2.

2. The modular charger according to claim 1, characterized in that said control unit (60) is further connected with a wireless transceiver (63), said wireless transceiver (63) being used for the mobile terminal (90) to send a control signal to the control unit (60) for cutting off the input and output of the charger.

3. A safety control method of a modular charger is characterized by comprising the following steps:

a control unit (60) configured to cut off the input and output of the charger;

a signal acquisition unit (50) at the rear end of a branch circuit used for connecting a load (40) is configured to acquire the waveform of load input current in real time, and electrical parameters at least containing the magnitude of the load input current are extracted;

generating an ideal input current waveform of a load (40) according to a rated output current i of a charger;

presetting a plurality of continuous detection periods, wherein each detection period comprises a plurality of continuous sub-periods;

comparing the acquired load input current waveform with an ideal input current waveform of a load (40) to obtain a matching parameter M in the sub-period, and generating a matching factor value X1 according to the matching parameter M;

calculating a quantity parameter N of the inrush current signal in the sub-period according to the extracted electrical parameter of the magnitude of the load input current, and generating a signal factor value X2 according to the quantity parameter N;

obtaining a judgment score X, X = (X1f1+ X2f2)/2 by weighted averaging of the matching factor value X1 and the signal factor value X2 in the same sub-period, wherein f1 is the weight of X1, and f2 is the weight of X2;

if the number of the sub-periods with the judgment value X larger than the preset value in one detection period is larger than the preset value, the control unit (60) cuts off the input and the output of the charger;

if the sub-period values of which the score X is larger than the preset score are smaller than or equal to the preset value in the detection period, the control unit (60) does not cut off the input and the output of the charger;

presetting an ideal input current waveform to contain C sudden-change current signals in a sub-period, wherein the matching factor value X1=1/M and the signal factor value X2= N/C;

the calculation method of the matching parameter M comprises the following steps:

calculating an area S1 enclosed by a part of an ideal input current waveform of the load (40) above a current i straight line and the current i straight line in the sub-period; calculating the area S2 enclosed by the part of the load input current waveform above the current i straight line and the current i straight line in the sub-period; calculating an area S3 enclosed by a part of an ideal input current waveform of the load (40) positioned below a current i straight line and the current i straight line in the sub-period; calculating the area S4 enclosed by the part of the load input current waveform under the current i straight line and the current i straight line in the sub-period; matching parameter M = (S1/S2+ S3/S4)/2;

alternatively, the first and second electrodes may be,

acquiring a current maximum value i1 of a part, above a current i straight line, of an ideal input current waveform of the load (40) in the sub-period; acquiring a current maximum value i2 of a part of a load input current waveform above a current i straight line in the sub-period; acquiring a current minimum value i3 of a part, below a current i straight line, of an ideal input current waveform of the load (40) in the sub-period; acquiring a current minimum value i4 of a part of a load input current waveform positioned below a current i straight line in the sub-period; matching parameter M = (i1/i2+ i4/i 3)/2.

Images