US20150033775A1

US20150033775A1 - Apparatus and Method for Monitoring and Controlling Load Requirements

Info

Publication number: US20150033775A1
Application number: US13/958,559
Authority: US
Inventors: Yedidia Cohen; Guanghui Wang; Zvi Kurtzman
Original assignee: Aura Systems Inc
Current assignee: Aura Systems Inc
Priority date: 2013-08-03
Filing date: 2013-08-03
Publication date: 2015-02-05

Abstract

An apparatus and method for monitoring and controlling load requirements relating to a transport refrigeration unit, including receiving one or more power information from a load: a power consumption information or a power requirement information; receiving one or more state information from the load: state of a compressor, state of a condenser, state of a compressor fan, state of an evaporation fan or state of a condenser fan; determining the following based on one or more power information and one or more state information: a) an amount of power to supply, b) a time duration for supplying power, and c) an operational frequency. In one example, one or more auxiliary information are also used for the determination: a fluid leakage measurement, a current measurement, a timer measurement, a counter measurement, a controlled environment temperature, or an environmental temperature.

Description

FIELD

This disclosure relates generally to apparatus and methods for monitoring and controlling load requirements. More particularly, the disclosure relates to monitoring and controlling load requirements relating to a transport refrigeration unit.

BACKGROUND

Providing adequate power to supply to load requirements in a transport system is particularly important, especially when one of the loads is a refrigeration unit that is part of a vehicle. Unlike other electrical loads, a refrigeration unit cannot be turned off if the refrigeration unit houses perishable goods. This provides a unique challenge in that whether the vehicle is moving or not, it must be assured that there is adequate power to supply the needs of the refrigeration unit and other load requirements, for example, those associated with operating the vehicle. For example, when the vehicle is not moving and with the engine off, there needs to be an alternate power source to supply the load requirements. Thus, it would be desirable to monitor the needs of the different loads and control the supply of power to meet the needs accordingly.

SUMMARY

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.
Disclosed is an apparatus and method for monitoring and controlling load requirements relating to a transport refrigeration. According to one aspect, a method for monitoring and controlling load requirements relating to a transport refrigeration unit, including receiving one or more of the following power information from a load: a power consumption information or a power requirement information; receiving one or more of the following state information from the load: state of a compressor, state of a condenser, state of a compressor fan, state of an evaporation fan or state of a condenser fan; determining the following based on one or more of the power information and one or more of the state information: a) an amount of power to supply, b) a time duration for supplying power, and c) an operational frequency.
According to another aspect, a method for monitoring and controlling load requirements relating to a transport refrigeration unit, including receiving one or more of the following power information from a load: a power consumption information or a power requirement information; receiving one or more of the following state information from the load: state of a compressor, state of a condenser, state of a compressor fan, state of an evaporation fan or state of a condenser fan; receiving one or more of the following auxiliary information: a fluid leakage measurement, a current measurement, a timer measurement, a counter measurement, a temperature information of a controlled environment, or an environmental temperature; and determining whether or not to send a fault code to inhibit power delivery to the load based on one or more of the power information, state information or auxiliary information.
According to another aspect, an apparatus for monitoring and controlling load requirements relating to a transport refrigeration unit, comprising a processor and a memory, the memory containing program code executable by the processor for performing the following: receiving one or more of the following power information from a load: a power consumption information or a power requirement information; receiving one or more of the following state information from the load: state of a compressor, state of a condenser, state of a compressor fan, state of an evaporation fan or state of a condenser fan; determining the following based on one or more of the power information and one or more of the state information: a) an amount of power to supply, b) a time duration for supplying power, and c) an operational frequency.
According to another aspect, an apparatus for monitoring and controlling load requirements relating to a transport refrigeration unit, comprising a processor and a memory, the memory containing program code executable by the processor for performing the following: receiving one or more of the following power information from a load: a power consumption information or a power requirement information; receiving one or more of the following state information from the load: state of a compressor, state of a condenser, state of a compressor fan, state of an evaporation fan or state of a condenser fan; receiving one or more of the following auxiliary information: a fluid leakage measurement, a current measurement, a timer measurement, a counter measurement, a temperature information of a controlled environment, or an environmental temperature; and determining whether or not to send a fault code to inhibit power delivery to the load based on one or more of the power information, state information or auxiliary information.
Advantages of the present disclosure may include modulating the amount of energy is supplied to a load (e.g., a refrigeration unit), saving energy by supplying each load with only the amount of energy needed, saving vehicle fuel when the vehicle engine is part of the power source for the loads, and increasing ability to modulate frequencies (e.g., Hz) to allow more efficient cooling for the transport refrigeration unit.
It is understood that other aspects will become readily apparent to those skilled in the art from the following detailed description, wherein it is shown and described various aspects by way of illustration. The drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example overview of an interface between a power source and a plurality of loads.

FIG. 2 illustrates an example of an input diagram with inputs from a plurality of loads and a plurality of auxiliary monitoring systems.

FIG. 3 illustrates an example monitoring and controlling unit including a processing unit coupled to a memory unit.

FIG. 4 illustrates an example flow diagram for monitoring and controlling load requirements relating to a transport refrigeration unit.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appended drawings is intended as a description of various aspects of the present disclosure and is not intended to represent the only aspects in which the present disclosure may be practiced. Each aspect described in this disclosure is provided merely as an example or illustration of the present disclosure, and should not necessarily be construed as preferred or advantageous over other aspects. The detailed description includes specific details for the purpose of providing a thorough understanding of the present disclosure. However, it will be apparent to those skilled in the art that the present disclosure may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the present disclosure. Acronyms and other descriptive terminology may be used merely for convenience and clarity and are not intended to limit the scope of the present disclosure.
While for purposes of simplicity of explanation, the methodologies are shown and described as a series of acts, it is to be understood and appreciated that the methodologies are not limited by the order of acts, as some acts may, in accordance with one or more aspects, occur in different orders and/or concurrently with other acts from that shown and described herein. For example, those skilled in the art will understand and appreciate that a methodology could alternatively be represented as a series of interrelated states or events, such as in a state diagram. Moreover, not all illustrated acts may be required to implement a methodology in accordance with one or more aspects.
FIG. 1 illustrates an example overview 100 of an interface between a power source 110 and a plurality of loads 150. As illustrated in FIG. 1, the interface between the power source 110 and the plurality of loads 150 also includes a monitoring and controlling unit 120. The monitoring and controlling unit 120 receives information from each of the plurality of loads 150 and analyzes the information. Although the present disclosure describes a plurality of loads, it is to be understood that the load may be a singular load, for example, a refrigeration unit or it may be various components (e.g., compressor, condenser, compressor fan, evaporation fan, condenser fan, etc.) of a refrigeration unit or various components of a load unit/system.
In one example, the information may be displayed on a display screen 130 that is coupled to the monitoring and controlling unit 120 through a display input line 131. A user (e.g., a vehicle operator) may use the information on the display screen 130 to execute one or more commands relating to the power supply to one or more of the plurality of loads. In one example, the user may input a command to the monitoring and controlling (M&C) unit 120 through the M&C input 121. In one example, the M&C input 121 is coupled to the display screen 130 such that the user may use the display screen to input commands to the monitoring and controlling unit 120.
In another example, the user may input a command directly to the power source 110 through a source input 111. In one example, the input 111 is coupled to the display screen 130 such that the user may use the display screen to input commands to the power source 110.
In one example, the plurality of loads 150 includes one or more of the following types of loads: a compressor of a refrigeration unit, a compressor fan, an evaporation fan, a condenser fan, or an electrical device, etc. For example, each load may have its unique power requirement which may vary as a function of, for example, operating time, operating cycles, power cycles, applications, etc. One feature of the monitoring and controlling unit is the ability to monitor each unique load requirement at a particular time frame and/or control the power supply to each load according to the unique load requirement at that particular time.
FIG. 1 illustrates a plurality of load condition lines 151 coupled to the monitoring and controlling unit 120. In one example, the load condition lines 151 supply power consumption information or power requirement information from the load 150 to the monitoring and controlling unit 120. Although a single load condition line 151 is illustrated between each load 150 and the monitoring and controlling unit 120, one skilled in the art would understand that multiple load condition lines 151 from each load to the monitoring and controlling unit 120 are within the scope and spirit of the present disclosure.
Once the power consumption information and/or power requirement information relating to a particular load is received by the monitoring and controlling unit 120, the monitoring and controlling unit 120 analyzes the power demand of the particular load. In one example, the monitoring and controlling unit 120 determines how much power should be delivered by the power source 110 to the particular load at a particular time frame by taking into account the power requirement of that particular load, the total power requirement of all the other loads and the power capacity of the power source 110 at that particular time frame.
As illustrated in FIG. 1, the monitoring and controlling unit 120 is coupled to the power source 110 through command line 125. In one example, following analysis of a received power consumption information or received power requirement information relating to a particular load, the monitoring and controlling unit 120 sends a command to the power source 110 to deliver a particular amount of power to the particular load, for example, for a specified time duration. In receiving the command from the monitoring and controlling unit 120, the power source 110 delivers an amount of power via power line 115 to the particular load, for example, for the specified time duration.
FIG. 2 illustrates an example of an input diagram 200 with inputs from a plurality of loads 150 and a plurality of auxiliary monitoring systems 140. As shown in FIG. 2, the monitoring and controlling unit 120 is coupled to the power source 110 through command line 125. FIG. 2 illustrates that the monitoring and controlling unit 120 receives inputs from the plurality of loads 150 through the plurality of load condition lines 151. In addition, the monitoring and controlling unit 120 may receive inputs from a plurality of auxiliary monitoring systems 140 through a plurality of auxiliary input lines 141. Once information is received, the monitoring and controlling unit 120 may display one or more of the received information on the display screen 130 (see FIG. 1). In one example, the monitoring and controlling unit 120 may analyze one or more of the information received or a combination of the information received to make a determination. In one example, the determination is displayed on the display screen 130. For example, the determination may include how much power should be delivered by the power source 110 to a particular load 150 and for what amount of specified time duration.
In one example, the inputs received by the monitoring and controlling unit 120 through the plurality of load condition lines 151 and the plurality of auxiliary input lines 141 may include one or more of the following: power consumption information, power requirement information, temperature information of a controlled environment within a vehicle, environmental temperature (for example, as being experienced by the vehicle), the state of a compressor of a refrigeration unit (such as, but not limited to, a “on” state, a “off” state and/or the speed of operation, and/or operational frequency), the state of a compressor fan (such as, but not limited to, a “on” state, a “off” state, and/or the speed of operation and/or operational frequency), state of an evaporation fan (such as, but not limited to, a “on” state, a “off” state and/or the speed of operation, and/or operational frequency), state of a condenser fan (such as, but not limited to, a “on” state, a “off” state and/or the speed of operation, and/or operational frequency), measurement of a fluid leakage sensor (a.k.a. “sniffer” sensor), measurement by a current sensor of current being drawn by any of the fans, the compressor, the condenser, etc., measurement by a timer of how long a particular unit (e.g., compressor, condenser, fan, refrigeration unit, etc.) has been “on”, measurement by a counter of how many times a particular unit (e.g., compressor, condenser, fan, refrigeration unit, etc.) has been “on” since the last reset. In one example, the fluid leakage sensor measures leakage of cooling fluid in a refrigeration unit. In one example, some of the inputs mentioned herein are measured at the plurality of loads 150 while others are measured at the plurality of auxiliary monitoring systems 140.
In one example, following receipt of information from one or more loads 150, a fault code (i.e., a fault message) is sent by the monitoring and controlling unit 120 to the power source 110 to inhibit power delivery to a particular load. In one example, the fault code is sent in the event of a fault for that particular load. In one example, a fault code is sent for an electrical short.
In one example, the monitoring and controlling unit 120 includes a processing unit (e.g., processor) coupled to a memory for analyzing the inputs received from the plurality of loads 150 and/or the plurality of auxiliary monitoring systems 140. FIG. 3 illustrates an example monitoring and controlling unit 120 including a processing unit 310 coupled to a memory unit 320. Although only one processing unit is shown and only one memory unit is shown, one skilled in the art would understand that multiple processing units and/or multiple memory units are within the scope and spirit of the present disclosure. Additionally, one skilled in the art would understand that, in one example, the memory unit(s) may be external to the monitoring and controlling unit 120. In one example, the monitoring and controlling unit 120 includes communication integrated circuit (IC) and/or additional peripheral integrated circuit (IC).
In one aspect, the monitoring and controlling unit 120 may include an electrical control unit (ECU). In some vernacular, the electrical control unit (ECU) is also known as an electronic control unit. In one example, the ECU is an embedded system that controls one or more of an electrical system or subsystems in the vehicle. In one example, the ECU includes a frequency modulation function and may be used to modulate the operational frequency of one or more of the loads 150.
In one example, the power source 110 may include a generator source for generating a direct current (DC) voltage or an unregulated alternating current (AC) voltage. In another example, the power source 110 is a direct current (DC) battery source. In yet another example, the power source 110 derives its power by plugging into a shore power grid, for example, while the vehicle is not in motion. While plugging into a shore power grid as its power source, the modulating and controlling unit 120 may include a frequency modulation function to modulate the frequency of the shore power. In one example, the monitoring and controlling unit 120 may detect the type of the power source (i.e., generator source, battery source or shore power source) being used, for example, by the vehicle for supplying the plurality of loads. And, in one example, when the monitoring and controlling unit 120 detects that the power source 110 is a shore power source, it may enable the frequency modulation function to modulate the frequency of the shore power. In one example, a 60 Hz power source may be modulated to another frequency based on the need of the load.
In one example, detection of the type of power source being used may be achieved by monitoring switches or indicators, which in one example, may be manually set to indicate the type of power source (generator, batter, shore power) being used. In another example, detection of the type of power source being used may be achieved by monitoring current levels on connection lines associated with the power source. One skilled in the art would understand that various other techniques not mentioned herein may be used to detect the type of power source being used and be within the scope and spirit of the present disclosure.
FIG. 4 illustrates an example flow diagram for monitoring and controlling load requirements relating to a transport refrigeration unit. In block 410, receive one or more of the following power information from a load: a power consumption information or a power requirement information. In block 420, receive one or more of the following state information from the load: state of a compressor, state of a condenser, state of a compressor fan, state of an evaporation fan or state of a condenser fan. In one example, the state indicates an “on” state, an “off” state or an operational frequency (e.g., at a particular Hz).
In block 430, receive one or more of the following auxiliary information: a fluid leakage measurement, a current measurement, a timer measurement, a counter measurement, a temperature information of a controlled environment, or an environmental temperature.
In one example, the fluid leakage sensor measurement indicates leakage of cooling fluid in a refrigeration unit. In one example, the fluid leakage measurement is measured by a fluid leakage sensor (a.k.a. “sniffer” sensor). In one example, the current measurement is measured by a current sensor, for example, of current being drawn by any of the fans (e.g., compressor fan, evaporation fan, condenser fan, etc.). In one example, the current measurement is measured by the current sensor, for example, of current being drawn by the compressor and/or the condenser.
In one example, the timer measurement is measured by a timer of how long a particular component or unit (e.g., compressor, condenser, compressor fan, evaporation fan, condenser fan, refrigeration unit, etc.) has been “on”. In one example, the counter measurement is measured by a counter of how many times a particular component or unit (e.g., compressor, condenser, compressor fan, evaporation fan, condenser fan, refrigeration unit, etc.) has been turned “on” or turned “off” since the last reset.
In block 440, determine whether or not to send a fault code to inhibit power delivery to the load based on one or more of the power information, state information or auxiliary information. In one example, the determination of whether or not to send a fault code is based on a predetermined threshold relating to indication of an electrical short. In one example, the fault code is sent to a power source.
In block 450, determine the following: a) an amount of power to supply (e.g., to the load), b) a time duration for supplying power (e.g., to the load), and c) an operational frequency (e.g., for supplying the power), based on one or more of the power information, state information or auxiliary information, and that no fault code is sent. In one example, the present disclosure includes any device that will monitor the frequency of the refrigeration compressor and will make a decision to increase the frequency or decrease it and/or will control the output power of the refrigeration and/or make a decision how to run the condenser and/or the evaporator fans. In an example, wherein the step in block 440 is not included, the step in block 450 is not dependent on whether or not a fault code is sent.
In block 460, send a command to a power source to deliver the amount of power for the time duration and at the operational frequency (e.g., to the load).
Although discrete lines coupling different units are shown in the examples of the figures, one skilled in the art would understand that the coupling may be wired or wireless coupling or a combination thereof as presented herein. In the event of wireless coupling, the units involved may include one or more wireless transceivers for the wireless coupling.
One skilled in the art would understand that the steps disclosed in the example flow diagram in FIG. 4 can be interchanged in their order without departing from the scope and spirit of the present disclosure. Also, one skilled in the art would understand that the steps illustrated in the flow diagram are not exclusive and other steps may be included or one or more of the steps in the example flow diagram may be deleted without affecting the scope and spirit of the present disclosure.
Those of skill would further appreciate that the various illustrative components, logical blocks, modules, circuits, and/or algorithm steps described in connection with the examples disclosed herein may be implemented as electronic hardware, firmware, computer software, or combinations thereof. To clearly illustrate this interchangeability of hardware, firmware and software, various illustrative components, blocks, modules, circuits, and/or algorithm steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware, firmware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope or spirit of the present disclosure.
For example, for a hardware implementation, the processing units (a.k.a. processor) may be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described therein, or a combination thereof. With software, the implementation may be through modules (e.g., procedures, functions, etc.) that perform the functions described therein. The software codes may be stored in memory units and executed by a processing unit. Additionally, the various illustrative flow diagrams, logical blocks, modules and/or algorithm steps described herein may also be coded as computer-readable instructions carried on any computer-readable medium known in the art or implemented in any computer program product known in the art. In one aspect, the computer-readable medium includes non-transitory computer-readable medium.
In one or more examples, the steps or functions described herein may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.
In one example, the illustrative components, flow diagrams, logical blocks, modules and/or algorithm steps described herein are implemented or performed with one or more processing units (e.g., processors). In one aspect, a processor is coupled with a memory which stores data, metadata, program instructions, etc. to be executed by the processor for implementing or performing the various flow diagrams, logical blocks and/or modules described herein.
The previous description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects without departing from the spirit or scope of the disclosure.

Claims

1. A method for monitoring and controlling load requirements relating to a transport refrigeration unit, comprising:

receiving one or more of the following power information from a load: a power consumption information or a power requirement information;

receiving one or more of the following state information from the load: state of a compressor, state of a condenser, state of a compressor fan, state of an evaporation fan or state of a condenser fan;

determining the following based on one or more of the power information and one or more of the state information:

a) an amount of power to supply,

b) a time duration for supplying power, and

c) an operational frequency.

2. The method of claim 1, further comprising sending a command to a power source to deliver the amount of power for the time duration and at the operational frequency.

3. The method of claim 1, further comprising receiving one or more of the following auxiliary information: a fluid leakage measurement, a current measurement, a timer measurement, a counter measurement, a temperature information of a controlled environment, or an environmental temperature.

4. The method of claim 3, wherein one or more of the auxiliary information is used in the determining step.

5. The method of claim 3, further comprising displaying one or more of the following power information, state information or auxiliary information on a display screen.

6. The method of claim 5, further comprising receiving an instruction from a user via the display screen.

7. The method of claim 3, wherein the fluid leakage measurement is a measurement of a cooling fluid leakage in the transport refrigeration unit.

8. The method of claim 3, wherein the current measurement is a measurement of current being drawn by one or more of a compressor, a condenser, a compressor fan, an evaporation fan or a condenser fan.

9. The method of claim 3, wherein the timer measurement is a measurement of how long in time duration one or more of the following has been turned ON: a compressor, a condenser, a compressor fan, an evaporation fan, a condenser fan, or the transport refrigeration unit.

10. The method of claim 3, wherein the counter measurement is a measurement of how many times one or more of the following has been turned ON or turned OFF since a last reset: a compressor, a condenser, a compressor fan, an evaporation fan, a condenser fan, or the transport refrigeration unit.

11. The method of claim 1, further comprising determining whether or not to send a fault code to inhibit power delivery to the load based on one or more of the power information or the state information.

12. The method of claim 1, wherein the state information includes one or more of the following state types: an “on” state, an “off” state or an operational frequency.

13. The method of claim 1, wherein the load is the transport refrigeration unit.

14. The method of claim 1, wherein the amount of power to supply to the load is also determined based on the capacity of a power source and the power demands on the power source by other loads.

15. A method for monitoring and controlling load requirements relating to a transport refrigeration unit, comprising:

receiving one or more of the following auxiliary information: a fluid leakage measurement, a current measurement, a timer measurement, a counter measurement, a temperature information of a controlled environment, or an environmental temperature; and

determining whether or not to send a fault code to inhibit power delivery to the load based on one or more of the power information, state information or auxiliary information.

16. The method of claim 15, further comprising sending a command to inhibit power delivery to the load.

17. The method of claim 15, wherein the current measurement is a measurement of current being drawn by one or more of a compressor, a condenser, a compressor fan, an evaporation fan or a condenser fan.

18. The method of claim 15, wherein the timer measurement is a measurement of how long in time duration one or more of the following has been turned ON: a compressor, a condenser, a compressor fan, an evaporation fan, a condenser fan, or the transport refrigeration unit.

19. The method of claim 15, wherein the counter measurement is a measurement of how many times one or more of the following has been turned ON or turned OFF since a last reset: a compressor, a condenser, a compressor fan, an evaporation fan, a condenser fan, or the transport refrigeration unit.

20. The method of claim 15, wherein the load is the transport refrigeration unit.

21. An apparatus for monitoring and controlling load requirements relating to a transport refrigeration unit, comprising a processor and a memory, the memory containing program code executable by the processor for performing the following:

a) an amount of power to supply,

b) a time duration for supplying power, and

c) an operational frequency.

22. The apparatus of claim 21, wherein the memory further comprising program code for sending a command to a power source to deliver the amount of power for the time duration and at the operational frequency.

23. The apparatus of claim 22, wherein the power source is one of the following: a generator source for generating a direct current (DC) voltage or an unregulated alternating current (AC) voltage, a direct current (DC) battery source, or a shore power source.

24. The apparatus of claim 21, wherein the memory further comprising program code for modulating the frequency of the shore power source.

25. The apparatus of claim 21, wherein the load is the transport refrigeration unit.

26. An apparatus for monitoring and controlling load requirements relating to a transport refrigeration unit, comprising a processor and a memory, the memory containing program code executable by the processor for performing the following:

27. The apparatus of claim 26, wherein the memory further comprising program code for sending a command to inhibit power delivery to the load.

28. The apparatus of claim 27, wherein the power source is one of the following: a generator source for generating a direct current (DC) voltage or an unregulated alternating current (AC) voltage, a direct current (DC) battery source, or a shore power source.

29. The apparatus of claim 26, wherein the memory further comprising program code for modulating the frequency of the shore power source.

30. The apparatus of claim 26, wherein the load is the transport refrigeration unit.