Patent Application
20200353797
The present disclosure relates to a method and system for charging a battery in a transport refrigeration system. More particularly, employing a battery charging system and methodology for improving efficiency and reliability of a battery therein.
A typical refrigerated cargo truck or refrigerated truck trailer, such as those utilized to transport a cargo via sea, rail or road, is a truck or trailer having a cargo compartment, modified to include a refrigeration unit located at one end of the truck or trailer. The refrigeration unit includes a compressor, condenser, expansion valve and evaporator serially connected by refrigerant lines in a closed refrigerant circuit in accord with known refrigerant vapor compression cycles. A power unit, including an engine, drives the compressor of the refrigeration unit, and is typically diesel powered, or in other applications natural gas powered. In many truck/trailer transport refrigeration systems, the compressor is driven by the engine shaft either through a belt drive or by a mechanical shaft-to-shaft link. In other systems, the engine drives a generator that generates electrical power, which in turn drives the compressor.
Manufacturers and operators of fleets of refrigerated trucks and refrigerated truck trailers desire to maximize operational efficiency of not only the refrigeration unit, but of the truck or tractor trailer system as a whole. In some systems transport refrigeration units include batteries to support operation of the refrigeration unit. These batteries include charging circuits to ensure that the batteries are always charged. However, sometimes as result of constant charging, the batteries may become excessively charged. Overcharging batteries reduces battery lifetime and wastes power.
According to one embodiment described herein is a method and system for charge management for a battery in a transport refrigeration unit. The method includes configuring the transport refrigeration unit with a plurality of DC power sources operable from a primary power source, connecting a first DC power source as a battery charger operably connected to the battery and configured to provide charging power to the battery, and connecting a second DC power source as a power source for at least one of a controller for the transport refrigeration system and a controller for the battery charger. The method also includes monitoring a current drawn by the battery and voltage of the battery and interrupting the charging of the battery based on the monitoring of a current drawn by the battery and voltage of the battery.
According to one embodiment described herein is a transport refrigeration unit. The transport refrigeration unit including a source of AC power, the source of AC power configured to supply power to an AC load of the transport refrigeration unit, a battery charging module operably connected to the source of AC power and configured to convert the AC power to a first DC power with a first DC power source and a second DC power with a second DC power source, and a battery operably connected to the first DC power source, the first DC power source configured as a DC power source for the battery. The transport refrigeration unit also including at least one of a controller of the transport refrigeration unit and a controller of the battery charging module operably connected to the second DC power source, the second DC power source supplying the second DC power for at least one of a controller of the transport refrigeration unit and a controller and a voltage monitor operably connected to the battery and to at least one of the controller of the transport refrigeration unit and the controller of the battery charging module, the voltage monitor configured to measure the voltage of the battery. The controller of the battery charging module is configured to interrupt the first DC power supplied from the first DC power source independent of the second DC power source based on at least the voltage of the battery.
In addition to one or more of the features described above, or as an alternative, further embodiments may include that the battery charging module disconnects the first DC power supplied from the first DC power source based on at least the voltage of the battery.
In addition to one or more of the features described above, or as an alternative, further embodiments may include that the controller of the battery charging module is configured to interrupt the first DC power source from supplying power to the battery based on at least the voltage of the battery independent of the second DC power source.
In addition to one or more of the features described above, or as an alternative, further embodiments may include that the battery charging module is an AC/DC converter to convert the AC power to DC power and at least one of the first DC power and the second DC power are regulated.
In addition to one or more of the features described above, or as an alternative, further embodiments may include that the second DC power source is isolated from the first DC power source under selected conditions.
In addition to one or more of the features described above, or as an alternative, further embodiments may include that the isolation is a diode isolation.
In addition to one or more of the features described above, or as an alternative, further embodiments may include that the isolation configured to ensure that the second DC voltage generated the second DC power source is isolated from the first DC power source and the battery, and first DC voltage from the first DC power source is transmitted as the second DC voltage if the second DC power source is inoperative.
In addition to one or more of the features described above, or as an alternative, further embodiments may include a current sensor operably connected to the battery and to at least one of the controller of the transport refrigeration unit and the controller of the battery charging module, the current sensor configured to measure the current supplied to or from the battery, wherein the controller of the battery charging module is further configured to interrupt of the first DC power source independent of the second DC power source based on at least the current supplied to or from the battery.
In addition to one or more of the features described above, or as an alternative, further embodiments may include at least one of an evaporator fan and a compressor, wherein the AC power source supplies AC power to the at least one of an evaporator fan and a compressor.
In addition to one or more of the features described above, or as an alternative, further embodiments may include that the source of AC power includes an engine and a generator.
In addition to one or more of the features described above, or as an alternative, further embodiments may include the battery supplying power to at least one of the controller of the transport refrigeration unit and the controller of the battery charging module when the first DC output is interrupted.
In addition to one or more of the features described above, or as an alternative, further embodiments may include that interrupting the charging of the battery includes disconnecting the first DC power supplied from the first DC power source.
In addition to one or more of the features described above, or as an alternative, further embodiments may include that the configuring includes converting the AC power to DC power and at least one of the first DC power and the second DC power are regulated.
In addition to one or more of the features described above, or as an alternative, further embodiments may include isolating the second DC power source from the first DC power source under selected conditions.
In addition to one or more of the features described above, or as an alternative, further embodiments may include that the isolating is configured to ensure that the second DC voltage generated the second DC power source is isolated from the first DC power source and the battery, and first DC voltage from the first DC power source is transmitted as the second DC voltage if the second DC power source is inoperative.
In addition to one or more of the features described above, or as an alternative, further embodiments may include measuring the current supplied to or from the battery with a current sensor operably connected to the battery and to at least one of the controller of the transport refrigeration unit and the controller of the battery charging module, wherein the interrupting of the first DC power source independent of the second DC power source is further based on at least the current supplied to or from the battery.
In addition to one or more of the features described above, or as an alternative, further embodiments may include configuring the transport refrigeration unit to include at least one of an evaporator fan and a compressor, wherein the AC power source supplies AC power to the at least one of an evaporator fan and a compressor.
In addition to one or more of the features described above, or as an alternative, further embodiments may include that the primary power source is an AC power source and includes an engine and a generator.
In addition to one or more of the features described above, or as an alternative, further embodiments may include supplying power to at least one of the controller of the transport refrigeration unit and the controller of the battery charging module from the battery when the first DC output is interrupted.
Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein. For a better understanding of the disclosure with the advantages and the features, refer to the description and to the drawings.
The foregoing and other features and advantages of embodiments are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
In general, embodiments herein relate generally to a battery charging circuit and configuration for the power system of a transport refrigeration unit. In particular separate outputs of the power system provide for power for the system, while a separate supply is employed for charging the battery. The system will provide an intelligently management for charging battery and at same time an independent power supply of all electronics components of unit to facilitate independent control. Such an architecture improves the function of the system in various operating modes by increasing efficiency and improving battery life and reliability.
For the purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of this disclosure is thereby intended. The following description is merely illustrative in nature and is not intended to limit the present disclosure, its application or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. As used herein, the term controller refers to processing circuitry that may include an application specific integrated circuit (ASIC), an electronic circuit, an electronic processor (shared, dedicated, or group) and memory that executes one or more software or firmware programs, a combinational logic circuit, and/or other suitable interfaces and components that provide the described functionality.
Additionally, the term “exemplary” is used herein to mean “serving as an example, instance or illustration.” Any embodiment or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments or designs. The terms “at least one” and “one or more” are understood to include any integer number greater than or equal to one, i.e. one, two, three, four, etc. The terms “a plurality” are understood to include any integer number greater than or equal to two, i.e. two, three, four, five, etc. The term “connection” can include an indirect “connection” and a direct “connection”.
As shown and described herein, various features of the disclosure will be presented. Various embodiments may have the same or similar features and thus the same or similar features may be labeled with the same reference numeral, but preceded by a different first number indicating the figure to which the feature is shown. Thus, for example, element “a” that is shown in Figure X may be labeled “Xa” and a similar feature in Figure Z may be labeled “Za.” Although similar reference numbers may be used in a generic sense, various embodiments will be described and various features may include changes, alterations, modifications, etc. as will be appreciated by those of skill in the art, whether explicitly described or otherwise would be appreciated by those of skill in the art.
Referring now to
Airflow is circulated into and through the cargo compartment of the trailer 106 by means of the transport refrigeration unit 120. A return airflow 134 flows into the transport refrigeration unit 120 from the cargo compartment of the trailer 106 through a refrigeration unit inlet 136, and across the evaporator 128 via the evaporator fan 130, thus cooling the return airflow 134. The cooled return airflow 134, now referred to as supply airflow 138, is supplied into the cargo compartment of the trailer 106 through a refrigeration unit outlet 140, which in some embodiments is located near the top wall 108 of the trailer 106. The supply airflow 138 cools the cargo 118 in the cargo compartment of the trailer 106.
The transport refrigeration unit power system 200 includes a control device 210 that connects the output of AC power source 132 to selected loads during various modes of operation of the transport refrigeration unit 120. In one embodiment the control device 210 connects the output of AC power source 132 to either the transport refrigeration unit 120 when the system calls for refrigeration or to auxiliary power connections, such as one or more DC power connections 204 and/or one or more AC power connections 206. When the control device operating in a first mode, the output of the AC power source 132 is connected to the compressor 122 and evaporator fan 130 of the transport refrigeration unit 120. When the control device 210 is in a second mode, the output of the AC power source 132 is connected to power conditioning modules 214 and 216, which are connected to the one or more DC power connections 204 or one or more AC power connections 206, respectively. A first power conditioning module 214 may be an AC to DC converter. The first power conditioning module 214 receives the unregulated, three-phase AC power from AC power source 132 and generates clean, stable, regulated and conditioned DC power (e.g., 24 VDC, 200 Amp). The regulated DC power is connected to the one or more DC power connections 204. The one or more DC power connections 204 may include, but not be limited to a DC battery charger. In another embodiment, the one or more DC power connections 204 may include a DC outlet, to which an operator can connect a DC load (e.g., soft drink pumps) or a DC load associated with the trailer, such as a lift gate.
A second power conditioning module 216 may optionally be employed as a DC to AC converter. The second power conditioning module 216 receives the clean, stable, regulated and conditioned DC power from the first power conditioning module 214 and produces clean, stable, regulated and conditioned AC power (e.g., 120/240 VAC, 20 Amp, 60 Hz). The regulated AC power is connected to the one or more AC power connections 206. The one or more AC power connections 206 may include an AC outlet, to which an operator can connect an AC load (e.g., cash registers, computers) or an AC load associated with the trailer (e.g., AC powered hand truck chargers).
A controller 230 controls various aspects of the transport refrigeration unit 120 and the transport refrigeration unit power system 200. Controller 230 can vary the speed of engine 160 depending on which mode of operation is selected.
Controller 230 also controls the control device 210.
Continuing with
Continuing with
In this way, the transport refrigeration system 100 is configured to provide battery charging and battery backup under all operating conditions for the transport refrigeration system 100 while ensuring that the battery 260 is not charged excessively and thereby impacting overall efficiency of the system 100 and in particular the reliability and operating life of the battery 260.
In addition, the current supplied to/from the battery 260 as measured by the current sensor 320 may optionally also be monitored to facilitate control of the charging of the battery 260. The method 400 continues at process step 450 with interrupting the charging of the battery 260 based on at least the monitored battery voltage, the current supplied to the battery 260, state of charge, temperature, time and the like. In addition, as depicted at line 452, select process steps may be recursively repeated to continuously monitor the charging state of the battery 260, and interrupting the charge as needed. Moreover, under selected conditions, once the first DC power source 312 has been interrupted and the controllers 230 or 330 are operating from the battery supplied power, if the battery state is such that additional charging is needed, the charging of the battery 260 is reinstated.
While the disclosure has been provided in detail in connection with only a limited number of embodiments, it should be readily understood that the present disclosure is not limited to such disclosed embodiments. Rather, embodiments can be modified to incorporate any number of variations, alterations, substitutions, combination, sub-combination, or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the disclosure. Additionally, while various embodiments have been described, it is to be understood that aspects of the disclosure may include only some of the described embodiments. Accordingly, embodiments are not to be seen as limited by the foregoing description, but only limited by the scope of the appended claims.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2018/000099 | 1/12/2018 | WO | 00 |
