Portable drawbar load banks and how they work

Abstract

A portable pull-rod load box has a control circuit board disposed on the upper part of the box body. The control circuit board is provided with a live wire terminal, a neutral wire terminal, a charging connection terminal, a control confirmation terminal, and a ground terminal from top to bottom. The live wire terminal is connected to the load master switch, a resistor A, and finally to the neutral wire terminal. Fan A is connected in parallel with resistor A, fan B is connected in parallel with resistor A, and the conversion switch is connected in series with the contactor and then connected in parallel with resistor A. The charging switch is a single-pole double-throw switch, the moving end of the charging switch is grounded, and the control confirmation terminal is connected to resistor C and then connected in two ways, one way is connected to one end of the fixed end of the charging switch, and the other way is connected to the other end of the fixed end of the charging switch through resistor B. The present invention has a reasonable structure, and the portable design is convenient for handling and moving, which improves the work efficiency and quality of on-site testers; the integrated national standard socket and control guide signal make the test more convenient, and the charging pile can be tested by directly plugging it in. The promotion and application have good economic and social benefits.

Description

Technical Field

[0001] The invention belongs to the technical field of on-site load testing and maintenance of AC and DC electric vehicle charging piles, and in particular relates to a portable pull-rod load box and a working principle thereof. Background Art

[0002] New energy vehicles have become one of the leading industries in my country and the world. my country's new energy vehicle industry has entered a golden period of development. In 2017, my country's new energy production and sales reached 794,000 and 777,000 respectively, with a cumulative ownership of 1.8 million vehicles, accounting for more than 50% of the global market ownership, ranking first in the world for three consecutive years. Ninety percent of new energy vehicles are electric vehicles that need to be charged, so charging facilities have become an important infrastructure for the development of new energy vehicles. At the same time, charging facilities have also become the biggest shortcoming restricting the rapid advancement of new energy vehicles. In the past two years, the relative lag of basic supporting facilities such as charging piles has become increasingly prominent. Although the number of charging piles is increasing rapidly, it cannot be ignored that the growth scale of new energy vehicles is still much higher than the growth scale of the number of charging piles, which means that the gap between cars and piles is still expanding. As of the end of 2017, my country has built about 210,000 public charging piles, with a total car-to-pile ratio of about 8:1, which is far from meeting the normal charging needs of new energy vehicles. The mature development of the charging pile industry is the basis for the further development of new energy vehicles. The further maturity of new energy vehicles will also promote the development of the charging pile industry; the two promote each other, complement each other, and are inseparable.

[0003] Charging piles are equipment used to charge electric vehicles (EVs) and are an alternative to traditional gas stations and gaspumps. Charging piles are mainly composed of pile bodies, electrical modules, metering modules, etc., and generally have functions such as power metering, billing, communication, and control. The charging pile equipment itself does not have a very high technical content, and the competitive differences are mainly reflected in the stability, compatibility, cost control, brand reputation, and bidding capabilities of the equipment produced. For a large number of built charging piles, there are problems such as on-site load testing and daily maintenance.

[0004] The current situation of similar load box products is as follows: the existing load box is mainly composed of a box body, load resistor elements, control devices, and cooling fans. The installation methods of the equipment are mainly divided into the following situations: a: mobile, with universal wheels at the bottom of the box body; b: portable, with handles on both sides of the cabinet body, portable; c: fixed, with fixed support feet or channel steel structure at the bottom; power supply method of cooling fan: equipment fan power supply, external independent power supply. The existing load box has the following technical defects in field use: 1) large size and heavy weight, which is not conducive to transportation; 2) the heat dissipation of the load resistor requires external power supply, and many test sites do not have power supply conditions; 3) at sites with power supply conditions, the power supply cable needs to be temporarily powered, and there are cable lines that are randomly pulled and messy, which poses a safety hazard; 4) using the terminal method, the charging pile cannot be directly connected, and the user also needs to make a guide circuit by himself and lead the main bus of the charging pile to the load box terminal separately.

[0005] How to design a device that is conducive to on-site load testing of AC and DC charging piles and how to improve the work efficiency of charging pile operation and maintenance personnel have become issues that need to be addressed urgently. Summary of the invention

[0006] The purpose of the present invention is to solve the above technical problems.

[0007] A portable pull rod load box comprises a box body, and universal wheels are arranged at the four corners of the bottom of the box body. The characteristics are: the top of the box body is provided with handles arranged symmetrically on the left and right, the rear end surface of the box body is provided with a telescopic pull rod, the right end surface of the box body is provided with an air inlet plate, and the left end surface of the box body is provided with an air outlet plate;

[0008] The upper part of the air inlet plate is provided with a switch assembly and an AC national standard socket from front to back. The switch assembly includes a charging switch at the bottom and a main load switch at the top.

[0009] A control circuit board is arranged on the upper part of the box body, and a live wire terminal, a neutral wire terminal, a charging connection terminal, a control confirmation terminal, and a ground terminal are arranged on the control circuit board from top to bottom. The live wire terminal is connected to the load main switch, resistor A in sequence, and finally connected to the neutral wire terminal. Fan A is connected in parallel with resistor A, fan B is connected in parallel with resistor A, and the conversion switch is connected in series with the contactor and then connected in parallel with resistor A.

[0010] The charging switch is a single-pole double-throw switch. The moving end of the charging switch is grounded. After the control confirmation terminal resistor C is connected, it is divided into two paths. One path is connected to one end of the fixed end of the charging switch, and the other is connected to the other end of the fixed end of the charging switch through resistor B.

[0011] The AC national standard socket is a single-phase socket, and the two ends of the single-phase socket are respectively a live wire end and a neutral wire end.

[0012] The conversion switch is a two-speed conversion switch.

[0013] The resistor B and the resistor C are both control guide resistors.

[0014] The fans A and B are both grounded.

[0015] The working principle of the portable pull rod load box is that after the charging switch control confirms the terminal resistance C, it is connected to the fixed end of the charging switch. When the path is connected, the output voltage is V;

[0016] When the charging switch control confirms the termination resistor C, it is connected to the other end of the fixed end of the charging switch through the resistor B. When the path is connected, the output voltage is V;

[0017] The load box uses an AC national standard socket as a test interface. Users can directly connect the gun head of the charging pile under test to the socket of the load box. The socket contains control guide resistors, namely resistors B and C. After the charging pile receives the control guide line number, it directly outputs charging normally. After the charging pile outputs charging, the cooling fan of the load box starts automatically. The user uses the load main switch to give the charging pile a certain load power to simulate the current value during direct charging, and observe whether the various functions of the charging pile are normal.

[0018] The present invention has a reasonable structure and a portable design, which is convenient for carrying and moving, and improves the work efficiency and quality of on-site testers. Control circuits such as fans do not require external power supply, which solves the problems of difficulty in obtaining power on site and long and messy cables, and eliminates safety hazards. The integrated national standard socket and control guide signal make testing more convenient, and the charging pile can be tested by directly plugging it in. The promotion and application of this invention has good economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a front view of a casing of the present invention.

[0020] Figure 2 It is a right view of a casing of the present invention.

[0021] Figure 3 It is a circuit structure principle diagram of the present invention.

[0022] In the figure: 1. Box body; 2. Handle; 3. Telescopic pull rod; 4. Live wire terminal; 5. Neutral wire terminal; 6. Charging connection terminal; 7. Control confirmation terminal; 8. Ground terminal; 101. Air inlet plate; 102. Universal wheel; 103. Air outlet plate; 104. AC national standard socket; 105. Charging switch; 106. Load main switch; 107. Resistor A; 108. Fan A; 109. Fan B; 110. Conversion switch; 111. Contactor; 112. Resistor B; 113. Resistor C. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the accompanying drawings, but this is not intended to limit the present invention.

[0024] The portable pull rod load box comprises a box body 1, and universal wheels 102 are arranged at the four corners of the bottom of the box body 1. The characteristics are: the top of the box body 1 is provided with a handle 2 arranged symmetrically on the left and right, the rear end surface of the box body 1 is provided with a telescopic pull rod 3, the right end surface of the box body 1 is provided with an air inlet plate 101, and the left end surface of the box body 1 is provided with an air outlet plate 103;

[0025] The upper part of the air inlet plate 101 is provided with a switch assembly and an AC national standard socket 104 from front to back, and the switch assembly includes a charging switch 105 at the bottom and a load main switch 106 at the top;

[0026] A control circuit board is arranged on the upper part of the box 1, and a live terminal 4, a neutral terminal 5, a charging connection terminal 6, a control confirmation terminal 7, and a ground terminal 8 are arranged on the control circuit board from top to bottom, wherein the live terminal 4 is connected to the load main switch 106 and the resistor A107 in sequence, and finally connected to the neutral terminal 5, the fan A108 is connected in parallel with the resistor A107, the fan B109 is connected in parallel with the resistor A107, and the conversion switch 110 is connected in series with the contactor 111 and then connected in parallel with the resistor A107;

[0027] The charging switch 105 is a single-pole double-throw switch, the moving end of the charging switch 105 is grounded, and the control confirmation terminal 7 is connected to the resistor C113 and then divided into two paths, one path is connected to one end of the fixed end of the charging switch 105, and the other path is connected to the other end of the fixed end of the charging switch 105 through the resistor B112;

[0028] The AC national standard socket 104 is a single-phase socket, and the two ends of the single-phase socket are respectively a live wire terminal 4 and a neutral wire terminal 5;

[0029] The conversion switch 110 is a two-speed conversion switch;

[0030] The resistor B112 and the resistor C113 are both control guide resistors;

[0031] The fan A108 and the fan B109 are both grounded.

[0032] In specific implementation, the present invention provides a solution that is more conducive to on-site testing for the current on-site load testing of AC and DC charging piles, which can greatly improve the work efficiency and quality of charging pile operation and maintenance personnel.

[0033] 1) Portable design: With the dual-purpose design of handheld and pull-rod type, on-site testers can directly put the portable pull-rod load box into the trunk of the car, and can directly pull it away like a suitcase when they arrive at the site, which greatly improves the work efficiency of on-site maintenance testers of charging piles;

[0034] 2) The traditional load box terminal is updated to a charging pile socket that complies with the national standard, so that the charging pile under test can be directly connected to the load box for testing;

[0035] 3) The fan power supply of the load box is directly powered by the output of the charging pile, which solves the problems of difficulty in obtaining power for on-site testing and potential safety hazards caused by randomly pulling cables at the power supply site;

[0036] 4) At sites with power supply conditions, the power supply cables do not need to be temporarily powered, which solves the problem of haphazard and messy cables and potential safety hazards.

[0037] Working principle of the present invention: The portable pull rod load box can be carried by hand and placed in the trunk of a car. The user can adjust the length of the telescopic pull rod 3 to move the load box on the ground according to the use requirements. The portable design is very convenient for carrying out on-site maintenance and testing.

[0038] When the charging switch 105 controls the confirmation terminal 7 to connect to the resistor C113, it is connected to the fixed end of the charging switch 105. When the path is connected, the output voltage is 6V;

[0039] When the charging switch 105 controls the confirmation terminal 7 to connect to the resistor C113, it is connected to the other end of the fixed end of the charging switch 105 through the resistor B112. When the path is connected, the output voltage is 9V;

[0040] The load box uses the national standard charging pile socket as the test interface. The user can directly connect the gun head of the tested charging pile to the socket of the load box. The socket contains a control guide resistor. After the charging pile receives the control guide line number, it directly outputs charging normally. After the charging pile outputs charging, the cooling fan of the load box starts automatically. The user uses the load main switch 106 to give the charging pile a certain load power to simulate the current value in the direct charging process, and observe whether the various functions of the charging pile are normal.

[0041] The above embodiments are merely examples for clearly explaining the present invention, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above descriptions. It is not necessary and impossible to list all the implementation methods here, and the obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A portable drawbar load box, comprising a box body (1), wherein four corners of the bottom of the box body (1) are provided with universal wheels (102), characterized in that: The top of the box body (1) is provided with a handle (2) arranged symmetrically on the left and right, the rear end surface of the box body (1) is provided with a telescopic pull rod (3), the right end surface of the box body (1) is provided with an air inlet plate (101), and the left end surface of the box body (1) is provided with an air outlet plate (103); The upper part of the air inlet plate (101) is provided with a switch assembly and an AC national standard socket (104) in sequence from front to back, wherein the switch assembly comprises a charging switch (105) at the bottom and a main load switch (106) at the top; A control circuit board is arranged at the upper part of the box body (1), and a live wire terminal (4), a neutral wire terminal (5), a charging connection terminal (6), a control confirmation terminal (7), and a ground terminal (8) are arranged on the control circuit board in order from top to bottom, wherein the live wire terminal (4) is connected to a load main switch (106), a resistor A (107) in order, and finally connected to the neutral wire terminal (5), a fan A (108) is connected in parallel with the resistor A (107), a fan B (109) is connected in parallel with the resistor A (107), and a conversion switch (110) is connected in series with a contactor (111) and then connected in parallel with the resistor A (107); The charging switch (105) is a single-pole double-throw switch, the moving end of the charging switch (105) is grounded, the control confirmation end (7) is connected to a resistor C (113) and then divided into two paths, one path is connected to one end of the fixed end of the charging switch (105), and the other path is connected to the other end of the fixed end of the charging switch (105) through a resistor B (112); The AC national standard socket (104) is a single-phase socket, and the two ends of the single-phase socket are respectively a live wire terminal (4) and a neutral wire terminal (5); the conversion switch (110) is a two-speed conversion switch.

2. The portable drawbar load box according to claim 1, characterized in that: The resistor B (112) and the resistor C (113) are both control guide resistors.

3. The portable drawbar load box according to claim 1, characterized in that: The fan A (108) and the fan B (109) are both grounded.

4. The method for using the portable drawbar load box is characterized by: The method for using the portable pull-rod load box is applied to the portable pull-rod load box according to any one of claims 1 to 3, when the charging switch (105) controls the confirmation terminal (7) to connect to the resistor C (113), and then connects to the fixed end of the charging switch (105), when the path is connected, the output voltage is 6V; When the charging switch (105) controls the confirmation terminal (7) to connect to the resistor C (113), it is connected to the other end of the fixed end of the charging switch (105) through the resistor B (112). When the path is connected, the output voltage is 9V; The load box uses an AC national standard socket (104) as a test interface. The user can directly connect the gun head of the charging pile to be tested to the socket of the load box. The socket contains control guide resistors, namely resistor B (112) and resistor C (113). After receiving the control guide line number, the charging pile directly outputs charging normally. After the charging pile outputs charging, the cooling fan of the load box starts automatically. The user uses the load main switch (106) to give the charging pile a certain load power to simulate the current value in the direct charging process, and observes whether the various functions of the charging pile are normal.

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