WO2022126697A1 - Charging and discharging apparatus - Google Patents

Abstract

Provided is a charging and discharging apparatus; the apparatus comprises a first switch tube (101), a second switch tube (102), a third switch tube (103), a fourth switch tube (104), a first equalization capacitor (105), a second equalization capacitor (106), a third filter capacitor (107), an inductor (108), and a control module (109); during charging, the input voltage is a high-level voltage provided by a DC bus, and the control module (109) is used for controlling the state of electrical conduction of the first switch tube (101), the second switch tube (102), the third switch tube (103), and the fourth switch tube (104) so as to convert the high-level voltage to low-level voltage to charge a battery; during discharging, the input voltage is a low-level voltage provided by the battery, and the control module is used for controlling the state of electrical conduction of the first switch tube (101), the second switch tube (102), the third switch tube (103), and the fourth switch tube (104) so as to convert the low-level voltage to a high-level voltage to supply power to an entire-vehicle system. The charging and discharging apparatus meets the application requirements of size reduction and light weight when applied to an entire-vehicle system of a motor vehicle.

Description

Charge and discharge device technical field

The present invention relates to the technical field of hybrid vehicles, in particular to a charging and discharging device.

Background technique

With the rapid development of industrial technology, energy conservation, emission reduction and low-carbon economy have received more and more attention from various industries. The development of battery application technology, the decrease of battery cost, the continuous improvement of energy density, and the reduction of battery volume and weight have made the application of power batteries in rail transit locomotives possible.

During the application of the power battery in the vehicle system, it is necessary to equip the power battery with a charging and discharging device. In the prior art, the charging and discharging device adopts the main circuit of a two-level bidirectional DC/DC DC chopper, which converts the intermediate DC bus voltage into the voltage required by the power battery for charging in the charging condition, and passes the battery voltage through the battery in the discharging condition. The bidirectional DC/DC charging and discharging device discharges to the DC bus for vehicle traction and auxiliary converters.

However, since the intermediate bus voltage level of the bidirectional DC/DC charging and discharging device in the prior art is 1800V, a higher-level IGBT device needs to be selected, which leads to the defects of large size and high cost of the charging and discharging device, which is not conducive to the use of the battery in the vehicle system. implementation in.

SUMMARY OF THE INVENTION

The purpose of the embodiments of the present invention is to provide a charging and discharging device, which meets the application requirements of miniaturization and light weight when the charging and discharging device is applied to the whole vehicle system of a locomotive.

An embodiment of the present invention provides a charging and discharging device, including: a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a first equalization capacitor, a second equalization capacitor, a third filter capacitor, and a reactor and control module;

The collector of the first switch tube is connected to the positive pole of the high-level voltage, the emitter is connected to the collector of the second switch tube, and the emitter of the second switch tube is connected to the collector of the third switch tube. electrode connection, the emitter of the third switch tube is connected to the collector of the fourth switch tube, the emitter of the fourth switch tube is connected to the negative pole of the high-level voltage, the first switch tube The collector of the third switch is connected to the positive pole of the low-level voltage, and the emitter of the third switch tube is connected to the negative pole of the low-level voltage;

Two ends of the first balancing capacitor are respectively connected to the collector of the first switch tube and the emitter of the second switch tube, and both ends of the second balancing capacitor are respectively connected to the third switch tube. The collector is connected to the emitter of the fourth switch tube, and both ends of the third filter capacitor are respectively connected to the emitter of the first switch tube and the emitter of the third switch tube;

The first end of the reactor is connected to the collector of the second switch tube, the second end of the reactor is connected to the collector of the fourth switch tube, and the third end of the reactor is connected the positive pole of the low-level voltage, and the fourth end of the reactor is connected to the negative pole of the low-level voltage;

The gates of the first switch tube, the second switch tube, the third switch tube and the fourth switch tube are all connected to the control module;

During charging, the input voltage is the high-level voltage provided by the DC bus, and the control module is used to control the first switch tube, the second switch tube, the third switch tube and the fourth switch tube In the conduction state, the high-level voltage is converted into a low-level voltage to charge the battery;

When discharging, the input voltage is the low-level voltage provided by the battery, and the control module is configured to control the first switch tube, the second switch tube, the third switch tube, and the fourth switch by controlling the The conduction state of the tube converts the low-level voltage into a high-level voltage to supply power to the vehicle system.

In a possible implementation manner, it further includes a first equalization resistor and a second equalization resistor;

Both ends of the first balancing resistor are respectively connected to the collector of the first switch tube and the collector of the third switch tube, and both ends of the second balancing resistor are respectively connected to the collector of the third switch tube. the collector is connected to the emitter of the fourth switch;

The first equalizing resistor and the second equalizing resistor are used to correct the midpoint potential voltage between the emitter of the second switch tube and the collector of the third switch tube.

In a possible implementation manner, the charging and discharging device further includes a low-frequency filter inductor and a slow-discharging resistor;

The first end of the low-frequency filter inductor is connected to the positive electrode of the high-level voltage, and the second end of the low-frequency filter inductor is connected to the collector of the first switch tube;

The first end of the slow discharge resistor is connected to the positive electrode of the low-level voltage, and the second end of the slow discharge resistor is connected to the negative electrode of the low-level voltage;

During charging and discharging, the low-frequency filter module is used to filter the voltage between the charging device and the high-level voltage;

The slow discharge resistor is used to discharge the filter capacitor of the charging and discharging device after the charging and discharging device is stopped.

In a possible implementation manner, the charging and discharging device further includes a protection module, and the protection module includes a first contactor, a second contactor, a protection resistor and a fuse;

The first end of the first contactor is connected to the first end of the fuse, the first end of the second contactor is connected to the first end of the first contactor, and the second contactor is connected to the first end of the first contactor. The second end of the protection resistor is connected to the first end of the protection resistor, the second end of the protection resistor is connected to the second end of the first contactor, and the second end of the first contactor is connected to the fuse The first end of the fuse is connected to the first end of the fuse, and the second end of the fuse is connected to the positive pole of the low-level voltage;

During charging, the first contactor is closed, the second contactor is opened, and the first contactor is used to control a high-level voltage to charge the battery;

During discharge, within a preset time period, the second contactor is closed and the first contactor is disconnected. The size of the charging current of the capacitor input;

When discharging, after a preset time period, the first contactor is closed, the second contactor is opened, and the first contactor is used to control the battery to supply power to the vehicle system.

In a possible implementation manner, the charging and discharging device further includes a first current sensor, a second current sensor, a third current sensor, a first voltage sensor, a second voltage sensor and a third voltage sensor;

The first end of the first current sensor is connected to the positive pole of the high-level voltage, and the second end of the first current sensor is connected to the first end of the low-frequency filter inductor for measuring high-level circuits current in;

The first end of the second current sensor is connected to the second end of the reactor, and the second end of the second current sensor is connected to the first end of the first contactor for measuring low level the current in the circuit;

The first end of the third current sensor is connected to the second end of the first contactor, and the second end of the third current sensor is connected to the first end of the fuse for measuring low level the current in the circuit;

the first voltage sensor is connected in parallel with the first equalization resistor, and is used for measuring the voltage across the first equalization resistor;

the second voltage sensor is connected in parallel with the second equalizing resistor, and is used for measuring the voltage across the second equalizing resistor;

The third voltage sensor is connected in parallel with the slow discharge resistor for measuring the voltage across the slow discharge resistor.

In a possible implementation, the charging and discharging device further includes an indicator light and a voltage dividing resistor;

The first end of the indicator light is connected to the collector of the first switch tube, the second end of the indicator light is connected to the first end of the voltage divider resistor, and the second end of the voltage divider resistor is connected to the the emitter of the fourth switch tube is connected;

The indicator light is used to indicate that the charging and discharging device is in a power-on state, and the voltage dividing resistor is used to reduce the voltage loaded on the indicator light.

In a possible implementation manner, the charging and discharging device further includes a first non-shielding case, a second non-shielding case and a shielding case;

The shielding case is used to install all devices with electromagnetic interference characteristics in the charging and discharging device;

the first unshielded shell is used for installing the control module;

The second unshielded shell is used for installing the first contactor, the second contactor, the protection resistor, the fuse, the first current sensor, the second current sensor, the third a current sensor and the fuse.

In a possible implementation manner, the first unshielded shell, the second unshielded shell and the shielded shell are all metal shells, and the charging and discharging device further includes a first high frequency filter and a second high frequency filter ;

The first high-frequency filter is flange-mounted on the first unshielded shell and the outer shell of the shielding shell, and the second high-frequency filter is flange-mounted on the second unshielded shell and the outer shell. On the outer shell of the shielding shell, the first unshielded shell and the second unshielded shell are integrated inside a device;

During charging, the second high-frequency filter prevents the electromagnetic interference of the charging and discharging device from being transmitted to the vehicle system;

During discharge, the first high-frequency filter prevents electromagnetic interference inside the charging device from being transmitted into the vehicle system.

In a possible implementation manner, the charging device further includes a cooling module;

The cooling module is installed outside the charging device, and is used for cooling the charging and discharging device by means of water cooling and heat dissipation.

In a possible implementation, the charging and discharging device further includes a reactor assembly case and a capacitor assembly case;

the reactor assembly shell, used for integrating the low-frequency filter inductor and the reactor inside the reactor assembly shell;

The capacitor assembly case is used for integrating the first equalization capacitor, the second equalization capacitor and the third filter capacitor inside the capacitor assembly case.

The embodiment of the present invention provides a charging and discharging device, the device includes: a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a first equalization capacitor, a second equalization capacitor, and a third filter capacitor , reactor and control module, the gates of the first switch tube, the second switch tube, the third switch tube and the fourth switch tube are all connected to the control module, when charging, the input voltage is the high-level voltage provided by the DC bus, The control module is used to convert the high-level voltage into a low-level voltage to charge the battery by controlling the conduction state of the first switch tube, the second switch tube, the third switch tube and the fourth switch tube; when discharging, the input The voltage is the low-level voltage provided by the battery, and the control module is used to convert the low-level voltage to a high-level by controlling the conduction states of the first switch tube, the second switch tube, the third switch tube, and the fourth switch tube The voltage supplies power to the vehicle system. The charging and discharging device provided by the embodiment of the present invention satisfies the application requirements of miniaturization and light weight when the charging and discharging device is applied to the whole vehicle system of a locomotive.

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description serve to explain the principles of the invention.

FIG. 1 is a schematic structural diagram 1 of a charging and discharging device according to an embodiment of the present invention;

FIG. 2 is a second structural schematic diagram of a charging and discharging device provided by an embodiment of the present invention;

FIG. 3 is a schematic diagram of a power feedback control provided by an embodiment of the present invention;

4 is a schematic diagram of a filter assembly of a charging and discharging device provided by an embodiment of the present invention;

5 is a schematic diagram of the appearance of a reactor assembly of a charging and discharging device provided by an embodiment of the present invention;

6 is a schematic diagram of a capacitor assembly of a charging and discharging device provided by an embodiment of the present invention;

FIG. 7 is a layout diagram of a charging and discharging device according to an embodiment of the present invention.

Description of reference numbers:

101: The first switch tube; 301: The first current sensor;

102: the second switch tube; 302: the second current sensor;

103: the third switch tube; 303: the third current sensor;

104: the fourth switch tube; 304: the first voltage sensor;

105: the first equalizing capacitor; 305: the second voltage sensor;

106: the second equalizing capacitor; 306: the third voltage sensor;

107: The third filter capacitor; 40: Protection module;

108: Reactor; 401: First Contactor;

109: control module; 402: second contactor;

201: The first equalizing resistor; 403: Protection resistor;

202: second equalizing resistor; 404: fuse;

203: low frequency filter inductor; 405: indicator light;

204: Slow release resistor; 406: Voltage divider resistor.

Detailed ways

By the above-mentioned drawings, there have been shown specific embodiments of the invention, which will be described in more detail hereinafter. These drawings and written descriptions are not intended to limit the scope of the inventive concept in any way, but to illustrate the inventive concept to those skilled in the art by referring to specific embodiments.

With the rapid development of industrial technology, energy conservation, emission reduction and low-carbon economy have received more and more attention from various industries. The development of battery application technology, the decrease of battery cost, the continuous improvement of energy density, and the reduction of battery volume and weight have made the application of power batteries in rail transit locomotives possible. Especially in the application field of diesel locomotives, it has obvious advantages. On the one hand, it can supplement the power shortage of diesel generator sets for diesel locomotives and greatly reduce the power requirements of diesel engines. The locomotive design can choose small diesel engines to reduce emissions; on the other hand, it can recover traction The motor braking feedback energy can better meet the short-cycle operation requirements of the locomotive, reduce the idle waiting time of the diesel engine, and enhance the application economy of the locomotive. At the same time, by using the power battery to provide power to the vehicle, the noise of the vehicle system can be effectively reduced. The use of hybrid diesel locomotives can greatly improve fuel economy and reduce emissions on the basis of existing technologies, which is one of the important measures to achieve energy saving and emission reduction.

In order to realize the charging and discharging function of the power battery, it is necessary to equip the vehicle with a charging and discharging device for the power battery. In the prior art, a two-level bidirectional DC/DC main circuit is used, and the intermediate DC bus voltage is converted into the voltage required by the power battery for charging in the charging condition, and the battery voltage is passed through the bidirectional DC/DC charging and discharging device in the discharging condition. Discharge to the DC bus for vehicle traction and auxiliary converters. However, the prior art adopts a two-level bidirectional DC/DC main circuit topology, which requires the power modules, capacitors, reactors, etc. of the bidirectional DC/DC charging and discharging device to be dispersed in the vehicle traction converter cabinet, which is not conducive to modularization extension. And because the voltage level of the intermediate bus is 1800V, the IGBT is selected at the 3300V level, and the switching frequency of the charging and discharging device is low, resulting in large volume, heavy weight and high cost of passive components such as capacitors and reactors. It is not conducive to the realization of modularization, miniaturization and light weight of the whole vehicle system.

The present invention aims to provide a charging and discharging device, comprising a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a first equalization capacitor, a second equalization capacitor, a third filter capacitor, a reactor, and The control module, when charging, the input voltage is the high-level voltage provided by the DC bus, and the control module is used to control the conduction state of the first switch tube, the second switch tube, the third switch tube and the fourth switch tube, and convert the high-level voltage. The level voltage is converted into a low-level voltage to charge the battery; when discharging, the input voltage is the low-level voltage provided by the battery, and the control module is used to control the first switch tube, the second switch tube, the third switch tube and the third switch tube. The conduction state of the four-switch tube converts the low-level voltage into a high-level voltage to supply power to the vehicle system, which meets the application requirements of miniaturization and light weight when the charging and discharging device is applied to the vehicle system of the locomotive.

FIG. 1 is a schematic structural diagram 1 of a charging and discharging device according to an embodiment of the present invention. As shown in FIG. 1 , the charging and discharging device in the embodiment of the present invention includes: a first switch tube 101 , a second switch tube 102 , a third switch tube 103 , a fourth switch tube 104 , a first balance capacitor 105 , and a second balance capacitor 106 , a third filter capacitor 107 , a reactor 108 and a control module 109 .

In the embodiment of the present invention, as shown in FIG. 1 , the collector of the first switch tube 101 is connected to the positive pole of the high-level voltage, the emitter of the first switch tube 101 is connected to the collector of the second switch tube 102, and the first switch tube 101 is connected to the collector of the second switch tube 102. The emitter of the second switch 102 is connected to the collector of the third switch 103, the emitter of the third switch 103 is connected to the collector of the fourth switch 104, and the emitter of the fourth switch 104 is connected to a high level The negative pole of the voltage, the collector of the first switch tube 101 is connected to the positive pole of the low-level voltage, and the emitter of the third switch tube 103 is connected to the negative pole of the low-level voltage. The two ends of the first equalizing capacitor 105 are respectively connected to the collector of the first switch 101 and the emitter of the second switch 102, and the two ends of the second equalizing capacitor 106 are respectively connected to the collector of the third switch 103 and the fourth The emitter of the switch tube 104 is connected, and both ends of the third filter capacitor 107 are connected to the emitter of the first switch tube 101 and the emitter of the third switch tube 103 respectively. The gates of the first switch transistor 101 , the second switch transistor 102 , the third switch transistor 103 and the fourth switch transistor 104 are all connected to the control module 109 . In the embodiment of the present invention, the first switch tube 101 , the second switch tube 102 , the third switch tube 103 , the fourth switch tube 104 , the first balance capacitor 105 , the second balance capacitor 106 , and the third filter capacitor 107 A three-level bidirectional DDC/DC topology circuit is formed, and the control module 109 controls the turn-on and turn-off of the first switch tube 101, the second switch tube 102, the third switch tube 103, and the fourth switch tube 104 respectively. The charging and discharging functions of the charging and discharging device are improved, and the voltage levels of the first switch tube 101, the second switch tube 102, the third switch tube 103, and the fourth switch tube 104 are also reduced, which is beneficial to the high frequency of the charging system.

The first end of the reactor 108 is connected to the collector of the second switch tube 102, the second end of the reactor 108 is connected to the collector of the fourth switch tube 104, and the third end of the reactor 108 is connected to a low-level voltage. The positive pole, the fourth terminal of the reactor 108 is connected to the negative pole of the low-level voltage.

During charging, the input voltage is the high-level voltage provided by the DC bus, and the control module 109 is used to control the conduction state of the first switch tube 101 , the second switch tube 102 , the third switch tube 103 and the fourth switch tube 104 , The high-level voltage is converted into a low-level voltage to charge the battery. Specifically, the charging and discharging device takes power from the DC bus of the locomotive, and filters it through the suppression circulating reactor at the input side. The ratio is greater than 50%. When the first switch tube 101 and the fourth switch tube 104 are turned on at the same time, the front-end voltage of the reactor 108 is a pulse width voltage of 1800V. When the first switch tube 101 and the fourth switch tube 104 When one is turned on, the first equalizing capacitor 105 and the second equalizing capacitor 106 divide the DC bus voltage of 1800V into two equalized 900V, and by discharging the power in the equalizing capacitor, the front-end voltage of the reactor 108 It is a 900V pulse width voltage. The output voltage is filtered by the reactor 108 and the third filter capacitor 107 to the voltage required for battery charging. During the working process, the third switch tube 103 and the first switch tube 101 cooperate with complementary conduction. The second switch tube 102 and the fourth switch tube 104 cooperate to conduct complementary conduction.

When discharging, the input voltage is the low-level voltage provided by the battery, and the control module 109 is used to control the conduction state of the first switch tube 101 , the second switch tube 102 , the third switch tube 103 and the fourth switch tube 104 to The low-level voltage is converted into a high-level voltage to supply power to the entire vehicle system. Specifically, the second switch tube 102 and the third switch tube 103 are turned on in a staggered manner of 180°, the duty ratios are equal, and the turn-on duty ratios are both less than 50%. The first switch tube 101 cooperates with the third switch tube 103 to conduct freewheeling. At this time, the battery voltage charges the first equalizing capacitor 105 through the reactor 108, and the anti-parallel diode of the fourth switch tube 104 cooperates with the second switch tube 102 to continue. The current is turned on, and at this time, the battery voltage charges the second equalizing capacitor 106 through the reactor 108 . At the same time, the first equalizing capacitor 105 and the second equalizing capacitor 106 are always discharging on the DC bus side in the whole process. The third filter capacitor 107 plays a role in regulating the output voltage of the battery during the entire discharge process.

The embodiment of the present invention provides a charging and discharging device, the device includes a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a first equalization capacitor, a second equalization capacitor, a filter inductor, a third switch The filter capacitor, the reactor and the control module, when charging, the input voltage is the high-level voltage provided by the DC bus, and the control module is used to control the first switch tube, the second switch tube, the third switch tube and the fourth switch tube. In the on state, the high-level voltage is converted into a low-level voltage to charge the battery; when discharging, the input voltage is the low-level voltage provided by the battery, and the control module 8 is used to control the first switch tube and the second switch tube by controlling , the conduction state of the third switch tube and the fourth switch tube, convert the low-level voltage into a high-level voltage to supply power to the vehicle system. The charging and discharging device provided by the embodiment of the present invention fully utilizes the three-level bidirectional DDC/DC topology circuit on the one hand, and controls the first switch tube, the second switch tube, the third switch tube and the fourth switch tube to conduct alternately, so as to realize The charging and discharging function of the charging and discharging device effectively reduces the volume and weight of the main circuit of the charging and discharging device, and meets the application requirements of miniaturization and light weight when the charging and discharging device is applied to the whole vehicle system of the locomotive.

In a specific embodiment, FIG. 2 is a second structural schematic diagram of a charging and discharging device provided by an embodiment of the present invention. As shown in FIG. 2 , the charging device may include: a first equalizing resistor 201 , a second equalizing resistor 202 , and a low-frequency filter inductor 203, slow discharge resistor 204, first current sensor 301, second current sensor 302, third current sensor 303, first voltage sensor 304, second voltage sensor 305, third voltage sensor 306, protection module 40, indicator light 405 , divider voltage 406 . The protection module 40 includes a first contactor 401 , a second contactor 402 , a protection resistor 403 and a fuse 404 .

In the embodiment of the present invention, both ends of the first equalization resistor 201 are respectively connected to the collector of the first switch transistor 101 and the collector of the third switch transistor 103, and both ends of the second equalization resistor 202 are respectively connected to the third switch transistor The collector of 103 is connected to the emitter of the fourth switch tube 104; the first equalization resistor 201 and the second equalization resistor 202 are used to correct the neutralization between the emitter of the second switch tube 102 and the collector of the third switch tube 103. point potential voltage. Specifically, the first equalizing resistor 201 and the second equalizing resistor 202 have the same parameters, and are supported by two equal DC support capacitors in series to correct the difference between the emitter of the second switch tube 102 and the collector of the third switch tube 103 . Midpoint potential voltage.

In the embodiment of the present invention, the first end of the low-frequency filter inductor 203 is connected to the positive electrode of the high-level voltage, and the second end of the low-frequency filter inductor 203 is connected to the collector of the first switch tube 101; The terminal is connected to the positive pole of the low-level voltage, and the second terminal of the slow discharge resistor 204 is connected to the negative pole of the low-level voltage; when charging, the low-frequency filter inductor 203 is used to filter the input high-level voltage to prevent the charging device from interacting with The other devices on the DC bus interact with each other to form a circulating current, which causes the instability of the vehicle system control. During discharge, the low-frequency filter inductor filters the discharge output voltage, and at the same time prevents other equipment pairs on the vehicle bus and the charging device from interacting with each other to form a circulating current, resulting in unstable control of the vehicle manufacturing system. The slow discharge resistor 204 discharges the filter capacitor of the charging and discharging device after the charging and discharging device is shut down, so as to prevent the filter capacitor from being charged after the shutdown and causing personal injury.

Specifically, when the charging and discharging device is charging, the high-level voltage provided by the DC bus is used as the input voltage of the charging and discharging device, and the input voltage is filtered by using the low-frequency filter inductor 203 as the suppression circulating inductor. When the charging and discharging device is discharging, the low-level voltage provided by the battery is used as the input voltage, and the reactor 108 is used as the energy storage inductance to store the voltage measured by the battery, thereby providing a high-level voltage for the DC bus.

In the embodiment of the present invention, the first end of the first current sensor 301 is connected to the positive pole of the high-level voltage, and the second end of the first current sensor 301 is connected to the first end of the low-frequency filter inductor 203 for measuring high-voltage The current in the level circuit is used for the current in the high level circuit. The first end of the second current sensor 302 is connected to the second end of the reactor 108, and the second end of the second current sensor 302 is connected to the first end of the first contactor 401 for measuring the current in the low-level circuit ; The first end of the third current sensor 303 is connected to the second end of the first contactor 401, and the second end of the third current sensor 303 is connected to the first end of the fuse 404 for measuring the current; the first voltage sensor 304 is connected in parallel with the first equalizing resistor 201 to measure the voltage across the first equalizing resistor 201; the second voltage sensor 305 is connected in parallel with the second equalizing resistor 202 and used to measure the voltage across the second equalizing resistor Voltage; the third voltage sensor 306 is connected in parallel with the slow discharge resistor 204 for measuring the voltage across the slow discharge resistor 204 .

Exemplarily, FIG. 3 is a schematic diagram of a power feedback control provided by an embodiment of the present invention. Exemplarily, when the charging and discharging device is charging, the voltage conversion control is performed by collecting the third voltage sensor 306, and the current closed-loop control is performed according to the collected current of the second current sensor 302; when the charging and discharging device is discharging, by using the first The voltages of the voltage sensor 304 and the second voltage sensor voltage 305 are subjected to closed-loop voltage control to adjust the output voltage, and the closed-loop control of the discharge output current is performed by collecting the current value of the first current sensor 301 to adjust the output current. Through the detection and control of the voltage and current during the charging process and the discharging process, the limit control of the charging and discharging power according to the state of the battery is realized.

Specifically, in order to prevent the voltage imbalance of the three-level midpoint potential, the pulses that control the first switch tube 101, the second switch tube 102, the third switch tube 103 and the fourth switch tube 104 are controlled separately, and the middle The design of the point potential balance correction link and the midpoint potential correction link should not be too large, and the correction range is too large, which will cause the output voltage to fluctuate greatly. Therefore, the present invention makes a special design for the midpoint potential balance correction link, and the specific design is as follows:

First, determine the unbalanced voltage uref1 allowed by the midpoint potential of the system, and use the difference between the voltage value measured by the first voltage sensor 304 and the voltage value measured by the second voltage sensor 305 as the actual voltage difference Δu of the midpoint potential, then The formula for the design of the midpoint potential unbalance correction coefficient is shown in 1:

Where k>0, β is a positive integer, and k and β can be obtained from multiple experimental data.

When the mid-point potential deviation is within the allowable range, the mid-point potential imbalance correction coefficient is small to meet better output voltage characteristics. When the mid-point potential deviation is large, the mid-point potential imbalance correction coefficient is large, so that the Effective control of midpoint potential deviation.

In the embodiment of the present invention, the first end of the first contactor 401 is connected to the first end of the fuse 404, the first end of the second contactor 402 is connected to the first end of the first contactor 401, and the second contactor The second end of the contactor 402 is connected to the first end of the protection resistor 403, the second end of the protection resistor 403 is connected to the second end of the first contactor 401, and the second end of the first contactor 401 is connected to the first end of the fuse 404. One end is connected, and the second end of the fuse 404 is connected to the positive pole of the low-level voltage; when charging, the first contactor 401 is closed, the second contactor 402 is disconnected, and the first contactor 401 is used to control the high-level voltage Charge the battery; when discharging, within a preset time period, the second contactor 402 is closed, the first contactor 401 is opened, the second contactor 402 and the protection resistor 403 are used to reduce the battery at the moment when the discharge begins to filter capacitor 107 and The charging current of the first equalizing capacitor 105 and the second equalizing capacitor. When discharging, after a preset time period, the first contactor 401 is closed, the second contactor 402 is opened, and the first contactor 401 is used to control the battery to supply power to the vehicle system.

Specifically, during discharge, within a preset time period, the second contactor 402 is closed, the first contactor 2121 is opened, and the second contactor 402 and the protection resistor 403 are used to reduce the battery’s The charging current of the third filter capacitor 107 and the first equalization capacitor 105 and the second equalization capacitor 106 prevents the battery output from overcurrent and filters the third filter capacitor 107 , the first equalization capacitor 105 and the second equalization capacitor. 106 Device damage caused by overcurrent.

When discharging, after a preset time period, when the voltage detected by the first voltage sensor 304, the voltage detected by the second voltage sensor 305, and the voltage detected by the third voltage sensor 306 reach the preset value, the The first contactor 401 is closed, and the second contactor 402 is opened after a preset period of time. The first contactor 401 is used to make the battery supply power to the vehicle system.

When the charging and discharging device is discharging, in order to prevent the voltage loaded on the charging and discharging device from being too large, the second contactor 402 is closed, the first contactor 401 is opened, and the second contactor 402 is set within a preset time period. And the protection resistor 403 reduces the voltage loaded on the first switch tube 101 , the second switch tube 102 , the third switch tube 103 and the fourth switch tube 104 to ensure the safety of the discharge process. And after a preset time period, the first contactor 401 is closed, the second contactor 402 is opened, and the battery is controlled to supply power to the vehicle system through the closing of the first contactor 401 . When the current of the charging and discharging device exceeds the maximum value for a period of time, the fuse 404 melts the melt according to the heat generated by itself, thereby disconnecting the circuit and ensuring the safety of the charging and discharging device.

In the embodiment of the present invention, the first end of the indicator light 405 is connected to the collector of the first switch tube 101 , the second end of the indicator light 405 is connected to the first end of the divider voltage 406 , and the second end of the divider voltage 406 is connected. The terminal is connected to the emitter of the fourth switch tube 104 ; the indicator light 405 is used to indicate that the charging and discharging device is in the power-on state, and the voltage divider 406 is used to reduce the voltage loaded on the indicator light 405 . The design of the indicator light 405 indicates that the current charging and discharging device is in an electrified state, preventing people from accidentally touching the electrified charging and discharging device and affecting personal safety.

It can be seen from the above embodiment that the midpoint potential of the three-level bidirectional DDC/DC topology circuit is formed by using the first equalizing resistor and the second equalizing resistor, which improves the voltage balance effect of the charging and discharging device; The signal jitter of the input voltage is improved, and the performance of the charging and discharging device is improved; by using a slow discharge resistor, the discharge function of the filter capacitor after the charging and discharging device is stopped is realized; by using the first current sensor, the second current sensor and the third current sensor The sensor, the first voltage sensor, the second voltage sensor and the third voltage sensor realize the feedback control of voltage and current to prevent excessive power; by installing indicator lights and voltage divider resistors on the charging and discharging device, the charging and discharging device is improved. safety features; by using the first contactor, the second contactor, the protection resistor and the fuse in the protection module, the safety of the charging and discharging device is ensured during the charging and discharging process.

In a specific embodiment, the charging and discharging device further includes a first non-shielding case, a second non-shielding case, a shielding case and a cooling module. Wherein, the first unshielded shell and the second unshielded shell are integrated in an unshielded area of the charging and discharging device, and the shielding shell is installed in the shielding area of the charging and discharging device. The shielding case is used to install all devices with electromagnetic interference characteristics in the charging and discharging device; the first unshielded case is used to install the control module 109 and the first current sensor 301; the second unshielded case is used to install the first contactor 401, the first Two contactors 402 , a protection resistor 403 , a fuse 404 , a second current sensor 302 , a third current sensor 303 and a fuse 404 .

In order to avoid the electromagnetic interference of the circuit inside the charging and discharging device to the vehicle system, the devices inside the charging and discharging device are divided into the first non-shielding area, the second non-shielding area and the second non-shielding Install the related devices with electromagnetic interference in the shielding area to prevent it from causing interference to the internal control unit of the charging and discharging device and external interference, such as reactors, capacitors, modules, etc. The input and output unit and the control unit of the charging and discharging device are installed in the first non-shielded area and the second non-shielded area.

Specifically, all devices with electromagnetic interference characteristics in the charging and discharging device include the first switch tube 101, the second switch tube 102, the third switch tube 103, the fourth switch tube 104, the control module 109, the first equalizing capacitor 105, the Two equalization capacitors 106, a third filter capacitor 107, a first equalization resistor 201, a second equalization resistor 202, a low frequency filter inductor 203, a reactor 108, a slow discharge resistor 204, a first voltage sensor 304, a second voltage sensor 305, At least one of the three voltage sensors 306 , the protection module 40 , the indicator light 405 and the voltage divider 406 . Specifically, the control module 109 is a control unit. The control unit provides the first switch tube 101 , the second switch tube 102 , the third switch tube 103 , and the fourth switch tube 104 with alternating pulse signals to realize the input voltage and output. Voltage conversion function.

In an embodiment of the present invention, the charging and discharging device further includes a cooling module. Specifically, the cooling module is installed outside the charging device, and is used for cooling the charging and discharging device by adopting a water-cooled heat dissipation method.

In a specific embodiment, FIG. 4 is a schematic diagram of a filter assembly of a charging and discharging device provided by an embodiment of the present invention. As shown in FIG. 4 , the charging and discharging device further includes a first high-frequency filter EMI1 and a second high-frequency filter EMI2. In order to reduce the overall volume of the charging and discharging device, EMI1 and EMI2 are integrated. The first unshielded shell, the second unshielded shell and the shielded shell are all metal shells. EMI1 and EMI2 are flange-mounted on the outer shell of the second unshielded shell and the shielded shell. The shielding shell is integrated inside an integrated device; when charging, the EMI1 is used to prevent the electromagnetic interference of the input voltage on the DC bus side from affecting the charging device system, and the second filtering high-frequency filter is used to prevent the electromagnetic interference inside the charging device. The interference is transmitted to the vehicle system.

When discharging, the EMI2 is used to reduce the electromagnetic interference of all the connecting wires inside the shielding case from being radiated to the inside of the first non-shielding case, and the EMI1 is used to prevent the electromagnetic interference inside the charging device from being transmitted to the whole vehicle system middle.

In the embodiment of the present invention, both EMI1 and EMI2 are electromagnetic interference (Electromagnetic Interference, EMI) filters. In order to prevent the impact of the charging and discharging device on the electromagnetic interference of the vehicle system, EMI1 and EMI2 are flange-mounted on the second On the outer shell of the unshielded shell and the shielded shell, EMI filters are equipped on the input side and output side of the charging and discharging device to reduce the electromagnetic interference of the charging and discharging device to the locomotive system.

In a specific embodiment, the charging and discharging device further includes a reactor assembly case. The reactor assembly case is used to integrate the low-frequency filter inductor 203 and the reactor 108 inside the reactor assembly case. In order to make full use of the space size of the cabinet, the low-frequency filter inductor 203 and the reactor 108 of the charging device are integrated into one, and the heat is dissipated by water cooling. At the same time, the integrated design reduces the water cooling interface of a group of reactors, which can reduce the leakage of the water cooling interface. risks of. FIG. 5 is a schematic appearance diagram of a reactor assembly of a charging and discharging device according to an embodiment of the present invention.

In a specific embodiment, the charging and discharging device further includes a capacitor assembly case. The capacitor assembly case is used to integrate the first equalization capacitor 105 , the second equalization capacitor 106 and the third filter capacitor 107 inside the capacitor assembly case. In the embodiment of the present invention, the first equalization capacitor 105, the second equalization capacitor 106 and the third filter capacitor 107 are designed in an integrated manner, a dry-type shellless structure is selected, and the height of the cabinet body 300mm is fully utilized. The lead terminals are drawn out in an internal series connection, and the capacitors are connected in series and parallel through the bus bar to achieve the purpose of reducing the overall volume. FIG. 6 is a schematic diagram of a capacitor assembly of a charging and discharging device provided by an embodiment of the present invention. As shown in FIG. 6 , a plurality of capacitors are installed inside the capacitor assembly, and 11 terminals are installed outside. Among them, the capacitance between the terminal 1 and the terminal 2 constitutes the third filter capacitor 107; the terminal P1, the terminal P2, and the terminal P3 are short-circuited to form a terminal P, and the terminal O1, the terminal O2, and the terminal O3 are short-circuited to form the terminal O. , short-circuit terminal N1, terminal N2, and terminal N3 as terminal N, all capacitances between terminal P and terminal O form the first equalizing capacitor 105, and all capacitances between terminal O and terminal N form the first equalizing capacitor 105. Two equalizing capacitors 106 .

FIG. 7 is a layout diagram of a charging and discharging device according to an embodiment of the present invention. As shown in FIG. 7 , exemplarily, the size parameters of the charging and discharging device provided in the embodiment of the present invention are: length 300 mm×width 960 mm×height 1400 mm, which satisfies the requirements of miniaturization and light weight when the charging and discharging device is applied in the vehicle system. Quantify design requirements. Specifically, the charging and discharging device can be divided into two areas: a shielded area and an unshielded area. The unshielded area includes the above-mentioned first unshielded shell and second unshielded shell, as well as EMI1 and EMI2, reactor components, capacitors components; the input unit includes a protection module 40, a first current sensor 301, a second current sensor 302 and a third current sensor 303; the control unit includes a control module 109, and the power module includes a first switch tube 101, a second switch tube 102, a third The three switch tubes 103 and the fourth switch tube 104; the water cooling pipeline is connected to the water circuit of the external water cooling and heat dissipation system, and is connected to the reactor assembly and the power module cooling plate through the water cooling pipeline, and the reactor 108 and all components in the power module are connected. to dissipate heat.

In the present invention, unless otherwise expressly specified and defined, a first feature "on" or "under" a second feature may be in direct contact between the first and second features, or the first and second features indirectly through an intermediary touch. Also, a first feature being "above", "over" and "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature "below", "below" and "below" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

In the above description, references to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples", etc. refer to the specific features, structures described in connection with the embodiment or example. , material or feature is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, those skilled in the art may combine and combine the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples, without conflicting each other.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features thereof can be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention. scope.

Claims (10)

1. A charging and discharging device, comprising: a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a first equalization capacitor, a second equalization capacitor, a third filter capacitor, a reactor, and control module;

   The collector of the first switch tube is connected to the positive pole of the high-level voltage, the emitter is connected to the collector of the second switch tube, and the emitter of the second switch tube is connected to the collector of the third switch tube. electrode connection, the emitter of the third switch tube is connected to the collector of the fourth switch tube, the emitter of the fourth switch tube is connected to the negative pole of the high-level voltage, the first switch tube The collector of the third switch is connected to the positive pole of the low-level voltage, and the emitter of the third switch tube is connected to the negative pole of the low-level voltage;

   Two ends of the first balancing capacitor are respectively connected to the collector of the first switch tube and the emitter of the second switch tube, and both ends of the second balancing capacitor are respectively connected to the third switch tube. The collector is connected to the emitter of the fourth switch tube, and both ends of the third filter capacitor are respectively connected to the emitter of the first switch tube and the emitter of the third switch tube;

   The first end of the reactor is connected to the collector of the second switch tube, the second end of the reactor is connected to the collector of the fourth switch tube, and the third end of the reactor is connected the positive pole of the low-level voltage, and the fourth end of the reactor is connected to the negative pole of the low-level voltage;

   The gates of the first switch tube, the second switch tube, the third switch tube and the fourth switch tube are all connected to the control module;

   During charging, the input voltage is the high-level voltage provided by the DC bus, and the control module is used to control the first switch tube, the second switch tube, the third switch tube and the fourth switch tube In the conduction state, the high-level voltage is converted into a low-level voltage to charge the battery;

   When discharging, the input voltage is the low-level voltage provided by the battery, and the control module is configured to control the first switch tube, the second switch tube, the third switch tube, and the fourth switch by controlling the The conduction state of the tube converts the low-level voltage into a high-level voltage to supply power to the vehicle system.
2. The charging and discharging device according to claim 1, further comprising a first equalizing resistor and a second equalizing resistor;

   Both ends of the first balancing resistor are respectively connected to the collector of the first switch tube and the collector of the third switch tube, and both ends of the second balancing resistor are respectively connected to the collector of the third switch tube. the collector is connected to the emitter of the fourth switch;

   The first equalizing resistor and the second equalizing resistor are used to correct the midpoint potential voltage between the emitter of the second switch tube and the collector of the third switch tube.
3. The charging and discharging device according to claim 2, further comprising a low frequency filter inductor and a slow discharge resistor;

   The first end of the low-frequency filter inductor is connected to the positive electrode of the high-level voltage, and the second end of the low-frequency filter inductor is connected to the collector of the first switch tube;

   The first end of the slow discharge resistor is connected to the positive electrode of the low-level voltage, and the second end of the slow discharge resistor is connected to the negative electrode of the low-level voltage;

   During charging and discharging, the low-frequency filter module is used to filter the voltage between the charging device and the high-level voltage;

   The slow discharge resistor is used to discharge the filter capacitor of the charging and discharging device after the charging and discharging device is stopped.
4. The charging and discharging device according to claim 3, further comprising a protection module, the protection module comprising a first contactor, a second contactor, a protection resistor and a fuse;

   The first end of the first contactor is connected to the first end of the fuse, the first end of the second contactor is connected to the first end of the first contactor, and the second contactor is connected to the first end of the first contactor. The second end of the protection resistor is connected to the first end of the protection resistor, the second end of the protection resistor is connected to the second end of the first contactor, and the second end of the first contactor is connected to the fuse The first end of the fuse is connected, and the second end of the fuse is connected to the positive pole of the low-level voltage;

   During charging, the first contactor is closed, the second contactor is opened, and the first contactor is used to control the high-level voltage to charge the battery;

   During discharge, within a preset time period, the second contactor is closed and the first contactor is disconnected. The size of the charging current of the capacitor input;

   When discharging, after a preset time period, the first contactor is closed, the second contactor is opened, and the first contactor is used to control the battery to supply power to the vehicle system.
5. The charging and discharging device according to claim 4, further comprising a first current sensor, a second current sensor, a third current sensor, a first voltage sensor, a second voltage sensor and a third voltage sensor;

   The first end of the first current sensor is connected to the positive pole of the high-level voltage, and the second end of the first current sensor is connected to the first end of the low-frequency filter inductor for measuring high-level circuits current in;

   The first end of the second current sensor is connected to the second end of the reactor, and the second end of the second current sensor is connected to the first end of the first contactor for measuring low level the current in the circuit;

   The first end of the third current sensor is connected to the second end of the first contactor, and the second end of the third current sensor is connected to the first end of the fuse for measuring low level the current in the circuit;

   the first voltage sensor is connected in parallel with the first equalization resistor, and is used for measuring the voltage across the first equalization resistor;

   the second voltage sensor is connected in parallel with the second equalizing resistor, and is used for measuring the voltage across the second equalizing resistor;

   The third voltage sensor is connected in parallel with the slow discharge resistor for measuring the voltage across the slow discharge resistor.
6. The charging and discharging device according to claim 1, further comprising an indicator light and a voltage dividing resistor;

   The first end of the indicator light is connected to the collector of the first switch tube, the second end of the indicator light is connected to the first end of the voltage divider resistor, and the second end of the voltage divider resistor is connected to the the emitter of the fourth switch tube is connected;

   The indicator light is used to indicate that the charging and discharging device is in a power-on state, and the voltage dividing resistor is used to reduce the voltage loaded on the indicator light.
7. The charging and discharging device according to claim 5, further comprising a first non-shielding case, a second non-shielding case and a shielding case;

   The shielding case is used to install all the devices with electromagnetic interference characteristics in the charging and discharging device;

   the first unshielded shell is used for installing the control module;

   The second unshielded shell is used for installing the first contactor, the second contactor, the protection resistor, the fuse, the first current sensor, the second current sensor, the third a current sensor and the fuse.
8. The charging and discharging device according to claim 7, wherein the first non-shielding shell, the second non-shielding shell and the shielding shell are all metal shells, and the charging and discharging device further comprises a first high-frequency filter and a second high frequency filter;

   The first high-frequency filter is flange-mounted on the first unshielded shell and the outer shell of the shielding shell, and the second high-frequency filter is flange-mounted on the second unshielded shell and the outer shell. On the outer shell of the shielding shell, the first unshielded shell and the second unshielded shell are integrated inside a device;

   During charging, the second high-frequency filter prevents the electromagnetic interference of the charging and discharging device from being transmitted to the vehicle system;

   During discharge, the first high-frequency filter prevents electromagnetic interference inside the charging device from being transmitted into the vehicle system.
9. The charging and discharging device according to claim 8, further comprising a cooling module;

   The cooling module is installed outside the charging device, and is used for cooling the charging and discharging device by means of water cooling and heat dissipation.
10. The charging and discharging device according to claim 9, further comprising a reactor assembly case and a capacitor assembly case;

    the reactor assembly shell, used for integrating the low-frequency filter inductor and the reactor inside the reactor assembly shell;

    The capacitor assembly case is used for integrating the first equalization capacitor, the second equalization capacitor and the third filter capacitor inside the capacitor assembly case.

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