KR102599082B1 - battery charging system and refrigerator truck including the same - Google Patents

Abstract

According to various embodiments of the present invention, a battery charging system for charging a battery that supplies power to a cooler for cooling an internal space and a refrigerated truck including the same are provided. The battery charging system includes a sensing unit that detects the voltage and current of the battery, an AC/DC generator that generates direct current power from an external AC power source, and supplies the direct current power to at least one of the cooler and the battery through power terminals. The AC/DC converter and the converter based on the voltage and current of the battery detected by the converter, the switch unit connected between the power terminals and the battery, and the sensing unit, and the data received from the cooler controller of the cooler. It includes a control unit configured to control the switch unit.

Description

Battery charging system and refrigerator truck including the same}

The present invention relates to a battery charging system for a refrigerated truck and a refrigerated truck including the same.

In general, a refrigerated truck is a type of special vehicle that uses a cooling system to cool the inside of the loading space, preventing spoilage of cargo contained in the loading space and maintaining freshness.

Conventionally, engine-driven cooling systems were used in refrigerated trucks. The engine-driven cooling system uses the generator of the refrigerated truck to convert the engine's rotational force into electrical energy. The compressor, which receives electrical energy from the generator, compresses the refrigerant to high temperature and pressure and supplies it to the condenser. The condenser cools and liquefies the compressed refrigerant, and the liquefied refrigerant passes through the expander and is maintained at a low pressure for easy vaporization. The refrigerant maintained at low pressure is supplied to the evaporator and evaporates by the evaporator, absorbing heat from the surroundings and performing heat exchange to generate cold air.

In an engine-driven cooling system, the engine of the refrigerated truck is connected to a generator through a belt, and the generator converts mechanical energy from the engine's rotational force into electrical energy and supplies it to the cooling system, driving the compressor, condenser, and evaporator of the cooling system. It's the way to do it.

However, in general, the output voltage of a generator increases as the rotational speed of the rotor increases, so in a refrigerated truck using a main-type engine-driven cooling system, the output voltage from the generator is irregular according to changes in the rotational speed of the engine, causing the compressor to fail. It operates unstable, and when the engine stops, the generator also stops, making the cooling system impossible to operate. Therefore, there is a problem that the inside of the loading space of the refrigerated truck cannot be maintained at a low temperature, thereby deteriorating the quality of the transported cargo.

Meanwhile, greenhouse gas reduction across the road transportation sector is being promoted by introducing and strengthening greenhouse gas/fuel efficiency management systems for trucks and buses. For example, in the case of cars that use diesel fuel, exhaust gas reduction devices (DMF) are installed and old vehicles are scrapped early. In addition, policies are being implemented to encourage eco-friendly vehicles that use LPG gas, electricity, and hydrogen as fuel. In addition, commercial trucks have also recently become electrified, and electric trucks are being developed and sold.

However, most refrigerated trucks currently use diesel engines, and the rotational power of the diesel engine is converted into electrical energy to drive the cooling system.

The problem to be solved by the present invention is to provide a battery charging system for charging a battery that supplies power to a cooler.

Another problem that the present invention seeks to solve is to provide a refrigerated truck equipped with a battery charging system that charges a battery that supplies power to a cooler for cooling the interior space.

According to one aspect of the present invention, a battery charging system for charging a battery that supplies power to a cooler for cooling an internal space includes a sensing unit that detects the voltage and current of the battery, and generating direct current power from an external alternating current power source, An AC/DC converter that supplies the direct current power to at least one of the cooler and the battery through power terminals, a switch unit connected between the power terminals and the battery, and the voltage of the battery detected by the sensing unit, and and a control unit configured to control the AC/DC converter and the switch unit based on current and data received from a cooler controller of the cooler.

According to one example, the control unit receives a temperature set value of the cooler and an internal temperature value of the internal space from the cooler controller, and based on the temperature set value, the internal temperature value, and the voltage of the battery, the AC /Can be configured to control the output of the DC converter.

According to another example, the control unit receives the voltage of the battery from the sensing unit, receives the temperature set value of the cooler and the internal temperature value of the internal space from the cooler controller, and receives the temperature set value and the internal temperature value of the internal space. Calculate the expected power consumption of the cooler and the chargeable power of the battery based on the temperature value, determine the amount of charging current based on the voltage of the battery and the chargeable power, and generate a PWM control signal corresponding to the amount of charging current. It may be configured to output to the AC/DC converter.

According to another example, the control unit may be configured to obtain an external temperature value and calculate the expected power consumption based on the temperature set value, the internal temperature value, and the external temperature value.

According to another example, the control unit determines whether the operation mode is a rapid cooling mode, and when operating in the rapid cooling mode, the difference between the internal temperature value and the temperature set value is greater than a preset reference temperature. , the switch unit between the power terminals and the battery is opened, and when the difference between the internal temperature value and the temperature set value is below the reference temperature, the battery is switched on based on the expected power consumption and the chargeable power. It may be configured to charge.

According to another example, the control unit may be configured to receive a signal indicating an operating state from the cooler controller and control the switch unit in response to the signal.

According to another example, the control unit receives the voltage of the battery from the sensing unit, determines the level of the charging voltage of the battery based on the voltage of the battery, and provides a PWM control signal corresponding to the level of the charging voltage. output to the AC/DC converter, and upon receiving a non-operation signal from the cooler controller, short-circuit the switch unit to charge the battery, and upon receiving an operation signal from the cooler controller, open the switch unit. there is.

According to another example, the switch unit includes a main switch connected between one of the positive battery terminals of the battery and one of the power terminals, and a pre-switch connected in series between the one battery terminal and the one power terminal. It may include a charge switch and a precharge resistor. The control unit may be configured to turn on the precharge switch, turn on the main switch in response to the non-operation signal, and turn off the main switch in response to the operation signal.

According to another example, the AC/DC converter may include a rectifier circuit that rectifies the AC voltage of the AC power source, and a DC/DC converter circuit that generates the direct current power from the output of the rectifier circuit according to a PWM control signal. You can. The control unit may include a battery control unit configured to receive information about the battery from the sensing unit and control the switch unit, and a converter control unit to control the DC/DC converter circuit through the PWM control signal.

According to another example, the control unit may be configured to determine the duty ratio of the PWM control signal based on information about the battery and data received from the cooler controller.

A refrigerated truck according to one aspect of the present invention includes a loading dock having an internal space for loading cargo, a battery for storing power, a cooler for cooling the internal space using power supplied from the battery, and controlling the cooler, a cooler controller configured to transmit data regarding the cooler, and a battery charging system as described above.

Since the refrigerated truck uses the power stored in the battery to operate the cooler, if the refrigerated truck is driven for a long time, the battery may be completely discharged and the cooler will stop operating, causing the temperature in the internal space to rise above the target set value. Additionally, when a refrigerated truck is left unattended for a long period of time, the temperature of the interior space of the loading bay is similar to or higher than room temperature, and the battery may also have a low state of charge due to self-discharge.

In this case, the battery charging system of the present invention can effectively perform the operation of the cooler and charging the battery at the same time.

If the capacity of the AC/DC converter is designed to be large, cooling and battery charging can be performed at the same time, but the size and weight of the AC/DC converter increases and manufacturing costs also increase. When reducing the capacity of the AC/DC converter, charging the battery and operating the cooler at the same time may cause a failure in the converter, so charging the battery must be stopped until the temperature of the internal space reaches the target set value. In this case, the time it takes to fully charge the battery increases, which limits the efficient operation of the refrigerated truck.

However, the battery charging system of the present invention receives data about the status of the cooler from the cooler controller, and based on this, uses some of the direct current power generated by the AC/DC converter to charge the battery when the cooler does not consume much power. You can use it. Therefore, by effectively performing the operation of the cooler and charging the battery at the same time while using a small capacity AC/DC converter, the direct current power generated by the AC/DC converter can be used efficiently.

Figure 1 schematically shows a refrigerated truck according to an embodiment.
Figure 2 shows a battery charging system according to one embodiment of the present invention.
Figure 3a shows power consumption according to the cooling temperature of the inverter type cooler, and Figure 3b shows power consumption according to the cooling temperature of the non-inverter type cooler.
Figure 4 is a flowchart for explaining the operation of the control unit of the battery charging system connected to the inverter-type cooler according to an embodiment of the present invention.
Figure 5 is a flowchart for explaining the operation of a control unit of a battery charging system connected to an inverter-type cooler according to another embodiment of the present invention.
Figure 6 is a flowchart for explaining the operation of a control unit of a battery charging system connected to a non-inverter type cooler according to an embodiment of the present invention.
Figure 7 specifically shows the control unit of the battery charging system according to an embodiment of the present invention.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments presented below, but can be implemented in various different forms, and should be understood to include all transformations, equivalents, and substitutes included in the spirit and technical scope of the present invention. do. The examples presented below are provided to make the disclosure of the present invention complete and to fully inform those skilled in the art of the scope of the invention. In describing the present invention, if it is determined that a detailed description of related known technologies may obscure the gist of the present invention, the detailed description will be omitted.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof. Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by these terms. The above terms are used only for the purpose of distinguishing one component from another.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In the description with reference to the accompanying drawings, identical or corresponding components are assigned the same drawing numbers and overlapping descriptions thereof are omitted. I decided to do it.

Figure 1 schematically shows a refrigerated truck 1000 according to an embodiment.

Referring to FIG. 1, the refrigerated truck 1000 includes a loading bay 11 having an internal space 10, a cooler 20 including a cooler controller, a battery 200, and a battery charging system 100. . The refrigerated truck 1000 further includes a power unit, wheels, a steering device, etc. to function as a vehicle.

The refrigerated truck 1000 refers to a vehicle equipped with a cooler 20 to cool the internal space 10 of the loading bay 11. The refrigerated truck 1000 may be in the form of a truck as illustrated in FIG. 1 .

Depending on the cooling temperature of the internal space 10, a refrigerated truck that can maintain a temperature of -18 degrees or lower and a refrigerated truck that can maintain a temperature of up to -5 degrees can be functionally divided, but in this specification, the refrigerated truck (1000) is a concept that encompasses refrigerated trucks and refrigerated trucks. That is, the present invention can be applied to a refrigerated truck equipped with a cooler 20.

The refrigerated truck 1000 may include a driving battery and a motor that generates rotational force using power from the driving battery. For example, the refrigerated truck 1000 may be a vehicle that runs on electricity.

According to another example, the refrigerated truck 1000 may be a hydrogen vehicle that uses a fuel cell that generates electricity by directly reacting hydrogen and oxygen in the air.

According to another example, the refrigerated truck 1000 may be an internal combustion engine vehicle that includes an engine that generates rotational force using fuel such as diesel, gasoline, LPG gas, etc.

Cargo may be loaded in the internal space 10 of the loading bay 11. The loading bay 11 may be surrounded by an insulating material to prevent cold air in the interior space 10 from escaping to the outside. The internal space 10 may be a space surrounded by an insulating material.

The battery 200 can store power to drive the cooler 20. Battery 200 includes battery cells. Battery cells included in the battery 200 and their connection methods may vary depending on the required voltage and required power amount of the cooler 20.

The cooler 20 can cool the internal space 10 using power supplied from the battery 200. Cooler 20 may include a compressor, condenser, and evaporator. The compressor compresses the refrigerant at high temperature and pressure and supplies it to the condenser. The condenser cools and liquefies the compressed refrigerant, and the liquefied refrigerant passes through the expander and is maintained at a low pressure for easy vaporization. The refrigerant maintained at low pressure is supplied to the evaporator and evaporates by the evaporator, absorbing heat from the surroundings and generating cold air. The evaporator may be located within the internal space 10, and the compressor and condenser may be located outside the storage compartment 11.

The cooler 20 can be divided into an inverter type cooler and a non-inverter type cooler. The cooler 20 will be described in more detail below with reference to FIGS. 3A and 3B.

Chiller 20 may be controlled by a chiller controller, and the chiller controller may be configured to transmit data regarding the chiller to battery charging system 100 . Data regarding the cooler may include, for example, a set temperature value of the cooler 20, an internal temperature value of the internal space 10, and an external temperature value outside the storage compartment 11.

Data about the cooler may indicate whether the cooler 20 is operating. For example, when the cooling system including the compressor, condenser, and evaporator of the cooler 20 operates, the cooler controller outputs an operation signal, and when the internal temperature value reaches the set temperature value and the cooling system does not operate, the cooler controller outputs an operation signal. The controller can output an inactive signal.

The battery charging system 100 is based on data transmitted from an AC/DC converter that generates direct current power for charging the battery 200 from an external AC power source, a battery control unit that manages the battery 200, and a cooler controller. It may include a converter control unit that controls the AC/DC converter.

The battery charging system 100 is described in more detail below.

Figure 2 shows a battery charging system 100 according to one embodiment of the present invention.

Referring to FIG. 2, the battery charging system 100 includes a control unit 110, a sensing unit 120, an AC/DC converter 130, and a switch unit 140.

The battery charging system 100 is connected to an external alternating current power source (AC), a cooler 20 including a cooler controller 21, and a battery 200, and converts the power of the external alternating current power source (AC) into direct current power. It is configured to drive the cooler 20 and charge the battery 200. When the external alternating current power source (AC) is disconnected, the battery charging system 100 provides the power stored in the battery 200 to the cooler 20.

The battery charging system 100 not only controls charging of the battery 200 using alternating current (AC) power, but also performs the function of a battery manager that manages and protects the battery 200.

The battery 200 stores power to drive the cooler 20 and can supply power to the cooler 20 when the connection to an external alternating current power source (AC) is disconnected. Battery 200 includes battery cells 201.

Battery cells 201 may include rechargeable secondary batteries. For example, the battery cell 201 may be a nickel-cadmium battery, a lead storage battery, a nickel metal hydride battery (NiMH), a lithium ion battery, or a lithium polymer battery. It may include at least one selected from the group consisting of polymer battery), etc.

The battery cells 201 included in the battery 200 are shown as connected in series in FIG. 2, but may also be connected in parallel or in a combination of series and parallel.

The sensing unit 120 can sense the voltage and current of the battery 200. The voltage of the battery 200 may mean the terminal voltage of the battery 200, that is, the battery voltage, and the current of the battery 200 may mean the charging current and discharging current of the battery 200, that is, the battery current. . The battery charging system 100 may include a current sensor (A), and the sensing unit 120 may sense the charging current and discharging current of the battery 200 using the current sensor (A).

The sensing unit 120 may further sense the cell voltage of each of the battery cells 201. The sensing unit 120 can sense the temperature of the battery 200. To this end, the battery charging system 100 may further include a temperature sensor disposed adjacent to the battery 200.

According to another example, the sensing unit 120 may sense the external temperature outside the loading bay 11 of FIG. 1 . To this end, the battery charging system 100 may further include a temperature sensor disposed externally.

The sensing unit 120 may include analog-to-digital converters for converting electrical signals received from each sensor into digital signals, and may be referred to as an analog front end (AFE).

The sensing unit 120 may transmit the sensed values to the control unit 110. For example, the sensing unit 120 may sense the battery voltage and transmit it to the control unit 110.

The AC/DC converter 130 generates direct current power from external alternating current power (AC) under the control of the control unit 110, and supplies it to the cooler 20 and the battery 200 through the power terminals T1 and T2. Direct current power can be supplied. The direct current power generated by the AC/DC converter 130 may be supplied to the cooler 20 and the battery 200 simultaneously, or may be supplied to only one of the cooler 20 and the battery 200.

Data regarding the output voltage and output current output by the AC/DC converter 130 may be provided to the control unit 110. The control unit 110 may control the magnitude of the output voltage and output current of the AC/DC converter 130 based on data regarding the output voltage and output current received from the AC/DC converter 130. For example, the control unit 110 can control the AC/DC converter 130 using a PWM control signal, and can adjust the duty ratio of the PWM control signal to increase the size of the output voltage or output current. For example, when the size of the output voltage or output current output by the AC/DC converter 130 is smaller than the target set value, the duty ratio of the PWM control signal can be increased.

The switch unit 140 may be connected between the power terminals T1 and T2 and the battery 200. In Figure 2, the switch unit 140 is connected between the positive electrode of the battery 200 and the power terminal (T1), but it may also be connected between the negative electrode of the battery 200 and the power terminal (T2).

The switch unit 140 includes a main switch 141 connected between the power terminal T1 and the battery 200, a precharge switch 142 connected in series between the power terminal T1 and the battery 200, and It may include a precharge resistor 143. The precharge switch 142 and the precharge resistor 143 may be connected in parallel with the main switch 141.

The size of the precharge resistor 143 may be set so that no inrush current is generated due to the difference between the direct current voltage generated by the AC/DC converter 130 and the voltage of the battery 200. In addition, the precharge resistor 143 flows into the battery 200 to prevent the direct current generated by the AC/DC converter 130 from flowing excessively into the battery 200 and preventing the cooler 20 from operating normally. It can perform the function of limiting the size of the current.

The control unit 110 may include a battery control unit 111 and a converter control unit 112. The battery control unit 111 may be configured to receive sensing values related to the battery 200 from the sensing unit 120 and control the switch unit 140. The battery control unit 111 may be configured to turn off the main switch 141 and the precharge switch 142 when an abnormal condition such as full charge, overdischarge, overcurrent, or high temperature occurs in order to protect the battery 200. .

The converter control unit 112 may be configured to receive the output voltage and output current from the AC/DC converter 130 and control the AC/DC converter 130 using a PWM control signal.

The control unit 110 may receive data about the cooler 20 from the cooler controller 20. The control unit 110 controls the AC/DC converter 130 and the switch unit 140 based on the voltage and current of the battery 200 detected by the sensing unit 120 and data received from the cooler controller 20. It can be configured to do so.

According to one embodiment, the control unit 110 receives the temperature set value of the cooler 20 and the internal temperature value of the internal space (10 in FIG. 1) from the cooler controller 20, and configures the temperature set value and the internal temperature value. and may be configured to control the output of the AC/DC converter 130 based on the voltage of the battery 200.

According to another embodiment, the control unit 110 may be configured to receive a signal indicating an operating state from the cooler controller 20 and control the switch unit 140 in response to the signal.

Figure 3a shows power consumption according to the cooling temperature of the inverter type cooler, and Figure 3b shows power consumption according to the cooling temperature of the non-inverter type cooler.

Referring to FIG. 3A, the amount of power consumption of an inverter-type cooler varies depending on the internal temperature of the internal space (10 in FIG. 1). When the difference between the internal temperature and the set temperature is large, maximum power is consumed, but as the internal temperature approaches the set temperature, the amount of power consumed decreases.

On the other hand, a non-inverter type cooler operates discretely depending on the difference between the internal temperature and the set temperature, as shown in FIG. 3B. In other words, whether or not to operate is determined based on the lower temperature limit and upper temperature limit set based on the set temperature. The non-inverter type cooler operates and the internal temperature decreases, but when the lower temperature limit is reached, the non-inverter type cooler stops operating. When the internal temperature rises to the upper temperature limit, the non-inverter type cooler operates again. By repeating this process, the internal temperature is maintained near the set temperature. While non-inverter type coolers have the advantage of being cheaper than inverter type coolers, they have the disadvantage of being subject to large changes in internal temperature.

Figure 4 is a flowchart for explaining the operation of the control unit of the battery charging system connected to the inverter-type cooler according to an embodiment of the present invention.

The operation of the control unit shown in FIG. 4 is the operation when the battery charging system 100 is connected to an external alternating current power source (AC), the inverter type cooler 20, and the battery 200 as shown in FIG. 2.

Referring to FIG. 4 along with FIG. 2 , the control unit 110 may receive the voltage of the battery 200 from the sensing unit 120 (S41).

The control unit 110 may receive the temperature set value of the cooler 20 and the internal temperature value of the internal space 10 from the cooler controller 21 (S42). The temperature set value of the cooler 20 means the target temperature of the internal space 10 set by the user (e.g., the user of the refrigerated truck 1000), and the cooler 20 sets the internal temperature of the internal space 10. It is configured to maintain the temperature at approximately the set value.

The control unit 110 may calculate the expected power consumption of the cooler 20 and the chargeable power of the battery 200 based on the temperature set value and the internal temperature value (S43).

The control unit 110 may include a memory storing a lookup table for calculating the expected power consumption of the cooler 20 based on the temperature set value and the internal temperature value. Data for calculating the expected power consumption stored in the look-up table may vary depending on the volume of the cooler 20 and the internal space 10, etc.

According to another example, the control unit 110 may obtain an external temperature value outside the storage compartment 11. The control unit 110 may be configured to calculate expected power consumption based on the external temperature value as well as the temperature set value and internal temperature value. The control unit 110 may receive the external temperature value from the cooler controller 21 in step S42. According to another example, the control unit 110 may receive an external temperature value from the sensing unit 120.

The control unit 110 can obtain the current supplied to the cooler 20. For example, although not shown, a current sensor is added between the terminals T1 and T2 and the cooler, and the magnitude of the current supplied to the cooler 20 can be detected using the current sensor. According to another example, the control unit 110 receives information about the output current of the AC/DC converter 130 from the AC/DC converter 130, and receives information about the current of the battery 200 from the sensing unit 120. Since is received, the current supplied to the cooler 20 can be calculated using Kirchhoff's current law.

The control unit 110 may update data in the lookup table based on the temperature set value and internal temperature value received from the cooler controller 21 and the magnitude of the current supplied to the cooler 20. The control unit 110 may learn the relationship between the temperature set value, the internal temperature value, and the magnitude of the current supplied to the cooler 20 using an artificial neural network, and may store the relationship expression obtained through learning in the form of a lookup table.

The control unit 110 may store information about the power that the AC/DC converter 130 can output in advance. The control unit 110 may calculate the chargeable power for charging the battery 200 by subtracting the expected power consumption of the cooler 20 from the maximum output power of the AC/DC converter 130. The control unit 110 may calculate the chargeable power of the battery 200 by subtracting the expected power consumption and power margin of the cooler 20 from the maximum output power of the AC/DC converter 130. The AC/DC converter 130 may output power exceeding the maximum power consumption of the cooler 20.

The control unit 110 may determine the amount of charging current based on the voltage and chargeable power of the battery 200 (S44). The control unit 110 may determine the amount of charging current by dividing the chargeable power by the voltage of the battery 200.

The control unit 110 may output a PWM control signal corresponding to the charging current amount to the AC/DC converter 130 (S45). The control unit 110 may control the AC/DC converter 130 so that the AC/DC converter 130 supplies output current corresponding to the amount of charging current to the battery 200. According to one example, the control unit 110 may adjust the duty ratio of the PWM control signal so that the current of the battery 20 received from the sensing unit 120 is equal to the charging current amount. According to another example, the control unit 110 configures the AC/DC converter 130 to output an output current having a size corresponding to the sum of the expected amount of current to be supplied to the cooler and the amount of charging current to be supplied to the battery 130) can be controlled. The control unit 110 may output a PWM control signal with a duty ratio corresponding to the sum of the expected amount of current to be supplied to the cooler and the amount of charging current to be supplied to the battery to the AC/DC converter 130.

The AC/DC converter 130 may operate by a PWM control signal received from the control unit 110 (S46). Some of the current output from the AC/DC converter 130 is supplied to the cooler 20 and the remaining part is supplied to the battery 200, so that the battery 200 can be charged (S47). The control unit 110 may control the main switch 141 and the precharge switch 142 to charge the battery 200. For example, the control unit 110 may first turn on the precharge switch 142, then turn on the main switch 141, and then turn off the precharge switch 142 again.

The control unit 110 may check whether the battery 200 is fully charged (S48). When the battery 200 is fully charged, the control unit 110 may block battery charging (S49). The control unit 110 may turn off both the main switch 141 and the precharge switch 142 to block battery charging.

If the battery 200 is not fully charged, the control unit 110 performs again from step S41 and operates the AC/DC converter 130 based on the temperature set value, internal temperature value, and voltage of the battery 200. The output can be controlled again.

Figure 5 is a flowchart for explaining the operation of a control unit of a battery charging system connected to an inverter-type cooler according to another embodiment of the present invention.

The operating method of the control unit shown in FIG. 5 has some steps added to the operating method of the control unit explained with reference to FIG. 4. Below, the description will focus on the added steps (S51 to S53).

After the control unit 110 receives the temperature set value of the cooler 20 and the internal temperature value of the internal space 10 from the cooler controller 21 in step 42, the control unit 110 determines the operation mode to be rapid cooling. You can check whether it is in mode (S51). Rapid cooling mode can be set by the user. The rapid cooling mode is a mode in which all direct current power generated by the AC/DC converter 130 is supplied to the cooler 20.

When operating in the rapid cooling mode, the control unit 110 may compare the difference between the internal temperature value and the temperature set value with a preset reference temperature (S52). If the difference between the internal temperature value and the temperature set value is greater than the preset reference temperature, the control unit 110 may turn off the main switch 141 between the power terminals T1 and T2 and the battery 200. The precharge switch 142 may also be turned off.

When the internal temperature decreases and the difference between the internal temperature value and the temperature set value becomes below the preset reference temperature, the control unit 110 calculates the expected power consumption of the cooler 20 according to the method described with reference to FIG. 4, and calculates the expected power consumption of the cooler 20. Based on this, the output of the AC/DC converter 130 can be controlled. Since steps S43 to S49 have been described previously with reference to FIG. 4, they will not be repeated.

According to another embodiment, the operation mode may be a charging priority mode. When operating in the charging priority mode, the control unit 110 may instruct the cooler controller 21 to operate in a low-speed cooling mode, and the cooler controller 21 operates by lowering the power of the cooler 20 at a preset rate. can do. For example, the power of the cooler 20 can be lowered to 50% of the maximum power. In this case, the control unit 110 may calculate the expected power consumption when the cooler 20 operates in the low-speed cooling mode based on the temperature set value and the internal temperature value in step S43.

Figure 6 is a flowchart for explaining the operation of a control unit of a battery charging system connected to a non-inverter type cooler according to an embodiment of the present invention.

The operation of the control unit shown in FIG. 6 is the operation when the battery charging system 100 is connected to an external alternating current power (AC), the non-inverter type cooler 20, and the battery 200 as shown in FIG. 2. .

Referring to FIG. 6 along with FIG. 2 , the control unit 110 may receive the voltage of the battery 200 from the sensing unit 120 (S61).

The control unit 110 may determine the level of the charging voltage of the battery 200 based on the voltage of the battery 200 (S62). For example, the battery 200 may be charged in a constant current charging mode or a constant voltage charging mode depending on the charging state. In the case of constant current charging mode, the magnitude of the charging voltage may be determined based on the voltage of the battery 200 and the charging current in the constant current charging mode. In the case of constant voltage charging mode, the magnitude of the charging voltage may be determined based on the charging voltage of the constant voltage charging mode.

The control unit 110 may output a PWM control signal corresponding to the level of the charging voltage determined in step S62 to the AC/DC converter 130. A PWM control signal with a duty ratio corresponding to the magnitude of the charging voltage may be provided to the AC/DC converter 130, and the AC/DC converter 130 may generate an output voltage corresponding to the magnitude of the charging voltage. .

The direct current power generated by the AC/DC converter 130 according to the PWM control signal is supplied to the cooler 20, and the cooler 20 can operate (S64). Chiller 20 is a non-inverter type and can operate discretely or be inactive (i.e., stopped).

The control unit 110 may turn on the precharge switch 142 and turn off the main switch 141. Since the precharge switch 142 is turned on, a small portion of the output current of the AC/DC converter 130 may be supplied to the battery 200 through the precharge resistor 143.

The control unit 100 may receive a signal indicating the operating state from the cooler controller 21. When the control unit 100 receives a non-operation signal from the cooler controller 21 (S66), the battery 200 can be charged by short-circuiting the switch unit 140 (S67). For example, the control unit 100 may turn on the main switch 141 so that most of the output current of the AC/DC converter 130 is supplied to the battery 200. In the constant current charging mode, the magnitude of the current supplied to the battery 200 from the AC/DC converter 130 is constant, and in the constant voltage charging mode, a constant output voltage from the AC/DC converter 130 is supplied to the battery 200. is approved.

The control unit 110 may check whether the battery 200 is fully charged (S68). When the battery 200 is fully charged, the control unit 110 may block battery charging (S69). The control unit 110 may turn off both the main switch 141 and the precharge switch 142 to block battery charging.

If the battery 200 is not fully charged, the control unit 100 may charge the battery 200 until an operation signal is received from the cooler controller 21.

When the control unit 110 receives an operation signal from the cooler controller 21 (S70), the switch unit 140 may be opened. For example, the control unit 110 may turn off the main switch 141. At this time, the control unit 110 may maintain the precharge switch 142 in the turn-on state. Thereafter, the control unit 100 may maintain the current state until it receives a non-operation signal from the cooler controller 21.

Figure 7 specifically shows the control unit 110 of the battery charging system 100 according to an embodiment of the present invention.

Referring to FIG. 7, the control unit 110 receives information about the battery 200 from the sensing unit (120 in FIG. 2), the battery control unit 111 configured to control the switch unit 140, and a PWM control signal. It includes a converter control unit that controls the DC/DC converter circuit 130 through (S5).

The control unit 110 may receive a signal S1 from the cooler controller 21. According to one example, the signal S1 may include data regarding the temperature setpoint and internal temperature value of the cooler 20. Signal S1 may further include data regarding external temperature values.

According to another example, the signal S1 may be a signal indicating the operating state of the cooler 20 and may be an operating signal or a non-operating signal.

The battery control unit 111 may receive a signal S2 regarding the battery 200. The signal S2 can be received through the sensing unit 120 of FIG. 2. Signal S2 may be the battery voltage or charge/discharge current of the battery 200. According to another example, signal S2 may include data regarding external temperature values.

The battery control unit 111 may output a control signal S4 for controlling the main switch 141 and a control signal S3 for controlling the precharge switch.

The AC/DC converter 130 may include a rectifier circuit 131 that rectifies the alternating current voltage of alternating current power (AC) and a DC/DC converter circuit 132 that generates direct current power from the output of the rectifier circuit 131. there is. The rectifier circuit 131 may be a bridge rectifier circuit using four diodes. The DC/DC converter circuit 132 may include a full-bridge converter circuit, an LLC tank, a series-parallel transformer, and a dual full-bridge rectifier circuit.

The AC/DC converter 130 may further include an EMI filter circuit between the alternating current power (AC) and the rectifier circuit 131. The AC/DC converter 130 may further include a power factor correction circuit between the rectifier circuit 131 and the DC/DC converter circuit 132. The AC/DC converter 130 further includes a high-frequency decoupling capacitor at the rear end of the rectifier circuit 131, a DC link capacitor at the front end of the DC/DC converter circuit 132, and an output capacitor at the rear end of the DC/DC converter circuit 132. It can be included.

The converter control unit 112 may exchange a signal S5 with the DC/DC converter circuit 132. Signal S5 may include data regarding the output voltage and output current of the DC/DC converter circuit 132, and this data is transmitted from the DC/DC converter circuit 132 to the converter control unit 112. The signal S5 may include a PWM control signal for the converter control unit 112 to control the DC/DC converter circuit 132.

The control unit 110 may be configured to determine the duty ratio of the PWM control signal S5 based on information on the battery 200 and data received from the cooler controller 21. The control unit 110 may control the output voltage or output current of the AC/DC converter 130 through the duty ratio of the PWM control signal S5.

The converter control unit 112 may output a signal to control the switch between the rectifier circuit 131 and alternating current power (AC).

The control unit 110 may receive a signal S6 that detects the magnitude of the AC current and AC voltage of the AC power source (AC) at the front end of the rectifier circuit 131.

As such, the present invention has been described with reference to the various embodiments shown in the drawings, but these are merely illustrative examples, and those skilled in the art will understand that various modifications and variations of the embodiments are possible therefrom. . Therefore, the true scope of technical protection of the present invention should be determined by the technical spirit of the attached patent claims.

Claims (11)

A battery charging system for charging a battery that supplies power to a cooler for cooling an interior space, comprising:
A sensing unit that detects the voltage and current of the battery;
an AC/DC converter that generates direct current power from an external alternating current power source and supplies the direct current power to at least one of the cooler and the battery through power terminals;
a switch unit connected between the power terminals and the battery; and
A control unit configured to control the AC/DC converter and the switch unit based on the voltage and current of the battery detected by the sensing unit and data received from the cooler controller of the cooler,
The control unit,
Receiving the voltage of the battery from the sensing unit,
Receiving a temperature set value of the cooler and an internal temperature value of the internal space from the cooler controller,
Calculating expected power consumption of the cooler and chargeable power of the battery based on the temperature set value and the internal temperature value,
Determine the amount of charging current based on the voltage of the battery and the chargeable power,
A battery charging system configured to output a PWM control signal corresponding to the amount of charging current to the AC/DC converter. In claim 1,
The control unit receives the temperature set value of the cooler and the internal temperature value of the interior space from the cooler controller, and outputs the AC/DC converter based on the temperature set value, the internal temperature value, and the voltage of the battery. A battery charging system configured to control. delete In claim 1,
The control unit is configured to obtain an external temperature value and calculate the expected power consumption based on the temperature set value, the internal temperature value, and the external temperature value. In claim 1,
The control unit,
Check whether the operation mode is rapid cooling mode,
When operating in the rapid cooling mode, if the difference between the internal temperature value and the temperature set value is greater than a preset reference temperature, opening the switch unit between the power terminals and the battery,
A battery charging system configured to charge the battery based on the expected power consumption and the chargeable power when the difference between the internal temperature value and the temperature set value is below the reference temperature. In claim 1,
The control unit is configured to receive a signal indicating an operating state from the cooler controller and control the switch unit in response to the signal. In claim 1,
The control unit,
Determine the magnitude of the charging voltage of the battery based on the voltage of the battery,
Outputting a PWM control signal corresponding to the magnitude of the charging voltage to the AC/DC converter,
When a non-operation signal is received from the cooler controller, the switch unit is short-circuited to charge the battery,
A battery charging system configured to open the switch unit upon receiving an operation signal from the cooler controller. In claim 7,
The switch unit,
a main switch connected between one of the positive battery terminals of the battery and one of the power terminals; and
A precharge switch and a precharge resistor connected in series between the one battery terminal and the one power terminal,
The control unit,
Turn on the precharge switch,
In response to the inactive signal, turning on the main switch,
A battery charging system configured to turn off the main switch in response to the operation signal. In claim 1,
The AC/DC converter is,
a rectifier circuit that rectifies the alternating current voltage of the alternating current power supply; and
A DC/DC converter circuit that generates the direct current power from the output of the rectifier circuit according to the PWM control signal,
The control unit,
a battery control unit configured to receive information about the battery from the sensing unit and control the switch unit; and
A battery charging system including a converter control unit that controls the DC/DC converter circuit through the PWM control signal. In claim 9,
The control unit is configured to determine the duty ratio of the PWM control signal based on information about the battery and data received from the cooler controller. A loading bay having an internal space for loading cargo;
Batteries to store power;
a cooler that cools the interior space using power supplied from the battery;
a cooler controller configured to control the cooler and transmit data about the cooler; and
A refrigerated truck comprising the battery charging system of any one of claims 1, 2, and 4 to 10.

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