阅读说明：本技术 具有自适应充电协议的电动车辆充电器 (Electric vehicle charger with adaptive charging protocol ) 是由 彼得·易卜拉欣 哈尼·瓦赫迪 让·胡格斯·德切内斯 马克·安德烈·佛盖特 于 2020-03-19 设计创作，主要内容包括：本公开提供了一种充电器,包括AC端口、连接到所述AC端口并且包括具有用于接收充电参数的输入的控制器的可变电压DC电源、可连接到所述连接器和所述DC电源的所述输入的接口,其中,所述接口执行将通过所述充电电缆连接器接收的关于所述电池的充电参数的电池管理系统电压命令转换为用于所述可变电压DC电源的所述输入,或者根据关于所述电池的测量的信息为所述可变电压DC电源产生定义用于所述电池的所述充电参数的所述输入。(The present disclosure provides a charger comprising an AC port, a variable voltage DC power source connected to the AC port and comprising a controller having an input for receiving charging parameters, an interface connectable to the connector and the input of the DC power source, wherein the interface performs conversion of a battery management system voltage command received through the charging cable connector regarding charging parameters of the battery into the input for the variable voltage DC power source or generates the input defining the charging parameters for the battery for the variable voltage DC power source from measured information regarding the battery.)

1. A charger, comprising:

-an AC port;

-a variable voltage DC power supply connected to the AC port and comprising a controller having an input for receiving charging parameters;

-a charging cable connector connectable to a battery;

-an interface connectable to the connector and the input of the DC power source; wherein the interface performs one of the following operations:

converting a battery management system voltage command received via the charging cable connector regarding a charging parameter of the battery to the input for the variable voltage DC power source; and is

Generating the input defining the charging parameters for the battery for the variable voltage DC power source in accordance with the measured information about the battery.

2. The charger of claim 1, wherein the interface is replaceable to convert different types of communication protocols.

3. The charger of claim 1 or 2, wherein the interface is a first interface that converts a first communication protocol, further comprising a second interface that converts a second communication protocol.

4. The charger of claim 3, wherein the first communication protocol and the second communication protocol are similar protocols.

5. The charger of claim 3, wherein the first communication protocol and the second communication protocol are different.

6. The charger of any one of claims 1 to 5, wherein the interface is modular and selected according to a battery type or BMS protocol.

7. The charger of claim 6, wherein the charger further comprises a housing, and wherein the modular interface is mounted on the housing.

8. A charger according to any of claims 1 to 7, wherein said variable voltage DC power is supplied from a three phase power supply.

9. A charger according to any of claims 1 to 8, wherein said variable voltage DC power is supplied from a single phase AC power source.

10. The charger of any one of claims 1 to 9, wherein the variable voltage DC power supply has at least one conversion module comprising:

-at least one high voltage capacitor for storing electric power at a high voltage;

-a circuit comprising:

-at least one inductor connected in series with the AC port;

-a low voltage capacitor;

-one of the following:

two diodes connected between a first AC input terminal and opposite ends of the high voltage capacitor; and

two high voltage switches connected between a first AC input terminal and opposite ends of the high voltage capacitor;

-two intermediate low voltage switches connected between said opposite ends of said high voltage capacitor and said opposite ends of said low voltage capacitor, and

-two terminal low voltage switches connected between said opposite end of said low voltage capacitor and a second AC terminal,

-wherein a DC load can be connected to the opposite end of the high voltage capacitor; and

-a controller having at least one sensor for sensing current and/or voltage in the circuit and connected to the gate inputs of the two intermediate low voltage switches and the two terminal low voltage power switches.

11. The charger of claim 10, wherein the controller is to operate the circuit in a boost mode in which the voltage of the high voltage capacitor is higher than the peak voltage of the AC input, and the two intermediate low voltage power switches and the two terminal low voltage power switches are switched in redundant switching states in response to a measurement of the voltage present at the low voltage capacitor to maintain the low voltage capacitor at a predetermined fraction of the required voltage for the high voltage capacitor and thus maintain the high voltage capacitor at the required high voltage, and the rectifier circuit powers the DC load and absorbs power as a five level active rectifier with low harmonics on the AC input.

12. A charger according to claim 10 or 11, wherein said variable voltage DC power supply comprises a housing containing a plurality of conversion module sockets, each said module including said circuit, said modules operating in parallel to provide DC power to said load.

13. The charger of any one of claims 10 to 12, wherein the interface is modular.

14. The charger of claim 13, wherein the charger further comprises a housing, and wherein the modular interface is mounted on the housing.

15. The battery charger of any of claims 1-13, wherein:

the rectifier circuit is a bi-directional rectifier/inverter circuit including an inductor connected in series with an AC port, a low voltage capacitor, two high voltage power switches connected between a first AC terminal and opposite ends of the high voltage capacitor, two intermediate low voltage power switches connected between the opposite ends of the high voltage capacitor and opposite ends of the low voltage capacitor, and two terminal low voltage power switches connected between the opposite ends of the low voltage capacitor and a second AC terminal; wherein a DC port is connectable to the opposite end of the high voltage capacitor;

the controller is a first controller for a rectifier mode having at least one sensor for sensing current and/or voltage in the bidirectional rectifier/inverter and connected to the gate inputs of the two high voltage power switches, the two intermediate low voltage power switches and the two terminal low voltage power switches for operating the rectifier circuit in a boost mode wherein the voltage of the high voltage capacitor is above the peak voltage of the AC input and the two high voltage power switches are controlled to be on and off at the frequency of the AC input and the two intermediate low voltage power switches and the two terminal low voltage power switches are switched in redundant switching states in response to a measurement of the voltage present at the low voltage to maintain the low voltage capacitor at a predetermined fraction of the desired voltage of the high voltage capacitor, and thus maintain the high voltage capacitor at the required high voltage, the rectifier circuit provides the DC load and absorbs power as a five-level active rectifier with low harmonics on the AC input; and is

The power converter further includes a second controller for inverter mode connected to the two high voltage power switches, the two intermediate low voltage power switches, and the two terminal low voltage power switches and configured to generate and apply signal waveforms to the two high voltage power switches, the two intermediate low voltage power switches, and the two terminal low voltage power switches, the signal waveforms including a first control signal for connecting the low voltage capacitor in series with the DC port and the AC port and charging to a predetermined value proportional to the voltage of the DC port, and a second control signal for disconnecting the low voltage capacitor from the DC port and connecting in series with the AC port to discharge the low voltage capacitor.

16. A method for using a converter having a first communication protocol with an Electric Vehicle (EV), the method comprising:

-receiving EV communications from the EV in a second communication protocol at a connector interface of the converter;

-converting the EV communication from the second communication protocol to the first communication protocol; and is

-controlling the converter to respond accordingly to the converted EV communication.

17. The method of claim 16, wherein converting the communication from the second communication protocol to the first communication protocol comprises:

judging whether the second communication protocol conforms to the first communication protocol of the converter;

relaying the EV communication without conversion if the second communication protocol conforms to the first communication protocol of the converter;

converting the EV communication from the second communication protocol to the first communication protocol if the second communication protocol does not conform to the first communication protocol of the converter.

18. The method of claim 16 or 17, wherein the EV communication is converted from the second communication protocol to the first communication protocol at the connector interface of the converter.

19. The method of claim 16 or 17, wherein the EV communication is converted from the second communication protocol to the first communication protocol at the controller of the converter.

20. The method of any of claims 16 to 19, further comprising:

transmitting converter communications in the first communication protocol; and is

Converting the converter communication from the first communication protocol to the second communication protocol; and is

Sending the converter communication to the EV.

21. The method of claim 20, wherein the converting the communication from the first communication protocol to the second communication protocol comprises:

judging whether the first communication protocol conforms to the second communication protocol of the EV;

relaying the converter communication without conversion if the first communication protocol conforms to the second communication protocol;

converting the converter communication from the first communication protocol to the second communication protocol if the first communication protocol does not conform to the second communication protocol.

22. The method of claim 20 or 21, wherein the converter communication is converted from the first communication protocol to the second communication protocol at the connector interface of the converter.

23. The method of claim 20 or 21, wherein the converter communication is converted from the first communication protocol to the second communication protocol from the controller of the converter.

Technical Field

The subject matter of the present application relates generally to the field of power management systems, and more particularly to power management systems that operate with power converters, such as Electric Vehicle (EV) chargers.

Background

This section is intended to provide a background or context to the invention that is recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.

Electric vehicles are becoming more and more popular as more and more people are interested in renewable and environmentally friendly energy sources using solar panels. In most cases, such technologies need to be connected to and work with the power grid or household electrical wiring. Furthermore, in areas where electricity rates are variable at different times of the day, the use of electric vehicles and/or solar energy may be more attractive to consumers if they can manage the consumption and production of their energy to benefit from cheaper energy rates.

Solar panels or photovoltaic (hereinafter "PV") systems have particular advantages as a pollution-free and emission-free energy source that typically produces Direct Current (DC) electricity. To use this energy source with household equipment, an inverter is typically used. An inverter is an electrical converter that converts the variable Direct Current (DC) output of Photovoltaic (PV) solar panels to utility frequency Alternating Current (AC) that can be fed into a commercial power grid or used by a local, off-grid power grid. There are several types of inverters used with solar panels, such as stand-alone inverters, grid-tied inverters, battery backup inverters, and intelligent hybrid inverters.

Since the power production of solar panels is fluctuating and may not be easily synchronized with the power consumption of the load, when no solar power generation is produced, it is necessary to store energy for later use, for example in a battery or other storage system to manage energy storage and consumption using a smart hybrid (smart grid) inverter.

In addition, electric vehicles ("EVs") are becoming increasingly popular. A new "class 3" charging system, such as the charger disclosed by the applicant in the international PCT patent application with serial number PCT/CA2018/051291, published as WO2019/071359 on 2019, 4-month, 18-th, can provide Direct Current (DC) power to a domestic charging unit in addition to Alternating Current (AC) power. It must be mentioned that, despite the generation of Direct Current (DC) electricity, the PV panel output cannot be fed directly to an EV vehicle to charge its batteries.

Because they are able to quickly charge EVs using the home grid, they may introduce significant loads into the home grid, and more into the entire grid. This means that when a class 3 charger is operating, introducing a new load into the premises wiring system may cause the wiring system to overload.

Likewise, the use of multiple AC units or high usage appliances may place a high load on the home's power budget.

Therefore, there is a need for an energy management system that allows users to manage their energy consumption, including charging their electric vehicles, based on their priorities, without overloading the grid of their home and without exceeding the budget defined for the home.

On the other hand, despite the fact that batteries and solar panels of EVs are good energy sources, it is currently difficult to use them to reduce the electrical load and/or benefit from the lower possible energy costs.

Accordingly, there is a need for a power management system that can manage power between different loads and sources to minimize household energy expenditures and/or assist the grid as needed.

Disclosure of Invention

The present disclosure provides, among other things, a novel and innovative solution to the above-mentioned needs in the art that will become apparent to those skilled in the art once given this disclosure.

The present disclosure provides a charger capable of adapting different communication protocols used by different EVs and their battery management systems by using an interface to convert the protocol received from the BMS before sending it to the controller unit of the charger.

The present disclosure is further advantageous in that it provides the charger with the ability to deliver power to two EVs with different communication protocols simultaneously using separate interfaces.

In one broad aspect, the present disclosure provides a charger comprising an AC port, a variable voltage DC power source connected to the AC port, and a controller having an input for receiving charging parameters, a charging cable connectable to a battery; an interface connectable to a connector and an input of a Direct Current (DC) power source, wherein the interface performs one of the following two tasks. First, a battery management system voltage command received through a charging cable connector regarding the charging parameters of the battery is converted into an input for the variable voltage DC power supply. Second, an input defining charging parameters for the battery is generated for the variable voltage DC power supply based on the measured information about the battery.

In some embodiments, the interface may be replaceable to convert different types of communication protocols. These communication protocols may be any protocol available in the art, such as the CHAdeMO or Tesla (Tesla) protocols.

Those skilled in the art will appreciate that the interface may be designed and programmed to work with any other type of protocol, providing flexibility to the charger and its capabilities.

In some embodiments, the charger may have two or more interfaces, each operating with a different communication protocol, such that the charger can charge multiple vehicles with different protocols simultaneously. For example, one connector may connect to a Tesla (Tesla) cable and charge an EV using the Tesla (Tesla) protocol, and another connector may connect to a CHAdeMO cable and charge an EV using the Tesla protocol. In one embodiment, the multiple interfaces of the charger may be the same, allowing the charger to charge multiple EVs.

In some embodiments, the charger may have an interface that may be modular and selected according to the battery type or BMS protocol. This may be done by having a backplane on which a modular interface can be added, or by mounting directly to the chassis of the charger.

In some embodiments, the charger may be powered by a three-phase power source and provide DC charging to the EV. Alternatively, the charger may be powered by a single phase AC power source.

In some embodiments, the variable voltage DC power supply has at least one conversion module. The conversion module comprises at least one high-voltage capacitor and a circuit for storing boosted power. The circuit includes at least one inductor connected in series with the AC port, a low voltage capacitor, two diodes or high voltage switches connected between a first AC input terminal and opposite ends of the high voltage capacitor, two intermediate low voltage switches connected between opposite ends of the high voltage capacitor and opposite ends of the low voltage capacitor, and two terminal low voltage switches connected between opposite ends of the low voltage capacitor and a second AC terminal. A DC load may be connected to the opposite end of the high voltage capacitor. The variable voltage DC power supply further comprises a controller having at least one sensor for sensing current and/or voltage in the circuit and connected to the gate inputs of the two intermediate low voltage switches and the two terminal low voltage power switches.

In one embodiment, the controller of the circuit may be operable to cause the circuit to operate in a boost mode in which the voltage of the high voltage capacitor is above the peak voltage of the AC input and the two intermediate low voltage power switches and the two terminal low voltage power switches are switched in a redundant switching state in response to a measurement of the voltage present on the low voltage capacitor to maintain the low voltage capacitor at a predetermined fraction of the required voltage for the high voltage capacitor to maintain the high voltage capacitor at the required high voltage, the rectifier circuit powering the DC load and absorbing power as a five level active rectifier with low harmonics on the AC input.

In one embodiment, a variable voltage DC power supply includes a housing that houses a plurality of conversion module receptacles, each module including circuitry, the modules operating in parallel to provide DC power.

In one embodiment, the circuit may be a bidirectional rectifier/inverter circuit including an inductor connected in series with the AC port, a low voltage capacitor, two high voltage power switches connected between a first AC terminal and opposite ends of the high voltage capacitor, two intermediate low voltage power switches connected between opposite ends of the high voltage capacitor and opposite ends of the low voltage capacitor, and two terminal low voltage power switches connected between opposite ends of the low voltage capacitor and a second AC terminal; wherein the DC port may be connected to an opposite end of the high voltage capacitor; the controller is a first controller for the rectifier mode having at least one sensor for sensing current and/or voltage in the bidirectional rectifier/inverter and connected to the gate inputs of the two high voltage power switches, the two intermediate low voltage power switches and the two terminal low voltage power switches for operating the rectifier circuit in a boost mode in which the voltage of the high voltage capacitor is above the peak voltage of the AC input and the two high voltage power switches are controlled to turn on and off at the frequency of the AC input and the two intermediate low voltage power switches and the two terminal low voltage power switches are switched in a redundant switching state in response to a measurement of the voltage present at the low voltage to maintain the low voltage capacitor at a predetermined fraction of the desired voltage for the high voltage capacitor to maintain the high voltage capacitor at the desired high voltage, a rectifier circuit as an AC input with a five level active rectifier with low harmonics to power and absorb power to a DC load; and the power converter further comprises a second controller for the inverter mode connected to the two high voltage power switches, the two intermediate low voltage power switches and the two terminal low voltage power switches and configured to generate and apply signal waveforms to the two high voltage power switches, the two intermediate low voltage power switches and the two terminal low voltage power switches, the signal waveforms comprising a first control signal for connecting the low voltage capacitor in series with the DC port and the AC port and charging to a predetermined value proportional to the voltage of the DC port, and a second control signal for disconnecting the low voltage capacitor from the DC port and connecting in series with the AC port thereby discharging the low voltage capacitor.

In one broad aspect, the present disclosure provides a method for using a converter having a first communication protocol with an Electric Vehicle (EV). The method includes receiving EV communications from the EV in a second communication protocol at a connector interface of the converter; converting the EV communication from the second communication protocol to the first communication protocol; and controls the converter to respond to the converted EV communication accordingly.

In some examples of the method, converting the communication from the second communication protocol to the first communication protocol may include determining whether the second communication protocol conforms to the first communication protocol of the converter. If the second communication protocol conforms to the first communication protocol of the converter, the EV communication can be relayed without conversion. If the second communication protocol does not conform to the first communication protocol of the translator, the EV communication is translated from the second communication protocol to the first communication protocol.

In some examples of the method, the EV communication may be converted from the second communication protocol to the first communication protocol at a connector interface of the converter.

In some examples of the method, the EV communication is converted from the second communication protocol to the first communication protocol at a controller of the converter.

In some other examples, the method may further comprise: transmitting the converter communication in a first communication protocol; converting the converter communication from the first communication protocol to the second communication protocol; and send the converter communication to the EV. In one example, converting the communication from the first communication protocol to the second communication protocol may include determining whether the first communication protocol conforms to the second communication protocol of the EV. The converter communication may be relayed without conversion if the first communication protocol conforms to the second communication protocol, and converted from the first communication protocol to the second communication protocol if the first communication protocol does not conform to the second communication protocol.

In some other examples, converter communications may be converted from a first communication protocol to a second communication protocol at a connector interface of the converter.

In one example, converter communication may be converted from a first communication protocol to a second communication protocol at a controller of the converter.

Drawings

Embodiments of the present application will be better understood with reference to the following drawings:

FIG. 1 shows a schematic diagram of an electric vehicle charging system having an interface capable of communicating with a battery management system, according to an embodiment of the invention.

FIG. 2 shows a schematic diagram of an electric vehicle charging system with two different interfaces capable of communicating with two battery management systems, according to an embodiment of the invention.

Fig. 3 shows a block diagram of a system according to one embodiment of the present disclosure, in which an interface switches communication between Battery Management Systems (BMSs) so that a charger can communicate with the BMSs.

FIG. 4 is a flowchart of the steps taken to deliver current by the system shown in FIG. 3.

Fig. 5 shows a block diagram of a system according to one embodiment of the present disclosure, wherein a charger has two interfaces capable of converting two different communication protocols received from two different BMSs.

FIG. 6 is a flowchart of the steps taken to deliver current by the system shown in FIG. 5.

Fig. 7 shows a block diagram of a system in which charging parameters of a battery are determined, according to one embodiment of the present disclosure.

FIG. 8 is a flowchart of the steps taken to deliver current by the system shown in FIG. 7.

Fig. 9 is a flow chart of a method disclosed herein according to one embodiment of the present disclosure.

Detailed Description

Reference throughout this specification to "one embodiment," "an embodiment," or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment," "in an embodiment," and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

Furthermore, the described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. Reference will now be made in detail to the preferred embodiments of the present invention.

In one broad aspect, the present disclosure provides a charger comprising an AC port, a variable voltage DC power source connected to the AC port, and the charger comprising a controller having an input to receive a charging parameter, a charging cable controller connectable to a battery; an interface connectable to the connector and an input of the DC power source, wherein the interface performs one of the following two tasks. First, a battery management system voltage command received through a charging cable connector regarding the charging parameters of the battery is converted into an input for the variable voltage DC power supply. Second, an input defining charging parameters for the battery is generated for the variable voltage DC power source based on the measurement information about the battery.

As shown in fig. 1, the present disclosure provides a charger 100 that is able to adapt different communication protocols used by different EVs and their battery management systems by using an interface 102 to convert the protocol received from the BMS 104 before sending it to the charger's controller unit.

Fig. 4 shows a flow chart of the charger shown in fig. 1. A Battery Management System (BMS)104 communicates with the interface 102 via a connector 108. The connector 108 is connected to a charging cable having a charging cable carrying current and a data cable carrying information such as Charging Parameters (CP). Connector 108 passes data received in the BMS communication protocol to interface 102. The interface converts the charging parameters and sends them to the controller 110, and the controller 110 controls the variable voltage DC power supply 112. The DC power source converts the power correspondingly received from the power source 106 and sends it to the connector 108, which will be sent directly from the connector 108 to the EV battery 118.

The present disclosure is further advantageous in that it may provide the charger 100 with the ability to deliver power to two EVs having different communication protocols simultaneously using separate interfaces. Figure 2 is a schematic illustration of this embodiment. Here, the charger has two interfaces 102 and 102 'that communicate independently with BMS 104 and 104' and can charge two cars with the same or different communication protocols at the same time.

Fig. 3 shows a block diagram of the charger 100 with only one interface 102 receiving current from the power source 106 through the AC port 502.

Likewise, fig. 5 illustrates a block diagram of an embodiment of the charger disclosed herein having two connectors 108 and 108 'and two interfaces 102 and 102' to provide independent charging to EV batteries 1 and 2.

In some embodiments, the interface may be replaceable to convert different types of communication protocols. These communication protocols may be any available in the art, such as CHAdeMO, Combined Charging System (CCS), or Tesla (Tesla) protocols.

Those skilled in the art will appreciate that the interface may be designed and programmed to accommodate any other type of protocol, providing flexibility to the charger and its capabilities.

In some embodiments, the charger may have two or more interfaces 102, each interface 102 operating with a different communication protocol, such that the charger can charge multiple vehicles simultaneously with different protocols. For example, one connector may connect to a Tesla (Tesla) cable and charge an EV using the Tesla protocol, and another connector may connect to a CHAdeMO cable and charge an EV using the Tesla protocol. In one embodiment, the multiple interfaces of the charger may be the same, allowing the charger to charge multiple EVs.

Fig. 6 illustrates a flow diagram of the charger 100 in an embodiment, the charger 100 having two interfaces and charging two vehicles independently of their protocol.

In some embodiments, the charger may have an interface that may be modular and selected as a function of the battery type or BMS protocol. This may be done by having a backplane on which a modular interface can be added, or by mounting directly to the chassis of the charger.

Fig. 7 shows the charger 100 with only one interface for charging the battery 702. In this case, interface 102 may determine the charging parameters needed for battery 702 based on different information it may receive. Information required by the interface 102 may be received through the user interface, defining the battery type and required charging voltage rate, etc.

Alternatively, the interface 102 may receive information such as temperature, voltage, current, etc. through measurement tools or sensors and calculate charging parameters accordingly. As is known in the art, battery temperature may be used to regulate the charge rate.

In another embodiment, the battery may have electronic circuitry containing charging parameters or other information about the battery, enabling the interface to determine the charging parameters or convert them.

Fig. 8 shows a flow chart for use by the charger when the interface 102 is used to charge the battery 702.

Referring now to fig. 9, an example of a method for communication between a converter having a first communication protocol and an EV having a second communication protocol has been shown. Block S902 illustrates receiving a communication at the interface 102. In some examples, this may occur in two ways, meaning that the converter and EV may communicate with each other through interface 102. The communication is then converted to other communication protocols as in block 906 and forwarded.

In some examples, the interface 102 may determine whether the communication protocols are in compliance, as in block 904. This is advantageous for unnecessarily converting communications from one communication protocol to another. In this example, the communication is only converted if it does not conform to the other communication protocol, otherwise, it will only be relayed as in block S908.

In some other examples, the interface is predefined for communication between two particular communication protocols and is fitted with a connector 108, while in some embodiments the interface may be a generic interface capable of receiving different protocols.

Those skilled in the art will appreciate that although the illustration is shown as a separate element in the different figures, it may be an integrated part of the controller of the converter.

In some embodiments, the converter may be powered by a three-phase power source and provide DC charging to the EV. Alternatively, the converter may be powered by a single phase AC power source with a suitable rectifier circuit.

In some embodiments, the variable voltage DC power supply has at least one conversion module. The conversion module may be a switching power conversion module that draws power from AC mains (e.g., split-phase 240V AC) while taking into account near unity power factor.

The conversion module may include at least one high voltage capacitor and circuitry for storing power at a voltage. The circuit may include at least one inductor in series with the AC port, a low voltage capacitor, two diodes or high voltage switches connected between the first AC input and opposite ends of the high voltage capacitor, two intermediate low voltage switches connected between opposite ends of the high voltage capacitor and opposite ends of the low voltage capacitor, and two terminal low voltage switches connected between opposite ends of the low voltage capacitor and the second AC terminal. A DC load may be connected to the opposite end of the high voltage capacitor. The circuit further includes a controller having at least one sensor for sensing current and/or voltage in the circuit and connected to the gate inputs of the two intermediate low voltage switches and the two terminal low voltage power switches.

In one embodiment, the controller of the circuit is operable to cause the circuit to operate in a boost mode in which the voltage of the high voltage capacitor is above the peak voltage of the AC input and the two intermediate low voltage power switches and the two terminal low voltage power switches are switched in a redundant switching state in response to a measurement of the voltage present on the low voltage capacitor to maintain the low voltage capacitor at a predetermined fraction of the required voltage of the high voltage capacitor to maintain the high voltage capacitor at the required high voltage, the rectifier circuit powering the DC load and absorbing power as a five level active rectifier with low harmonics on the AC input.

In one embodiment, a variable voltage DC power supply includes a housing that houses a plurality of conversion module receptacles, each module including circuitry, the modules operating in parallel to provide DC power.

In one embodiment, the circuit may be a bidirectional rectifier/inverter circuit, the circuit including an inductor in series with the AC port, a low voltage capacitor, two high voltage power switches connected between a first AC terminal and opposite ends of the high voltage capacitor, two intermediate low voltage power switches connected between opposite ends of the high voltage capacitor and opposite ends of the low voltage capacitor, and two terminal low voltage power switches connected between opposite ends of the low voltage capacitor and a second AC terminal; wherein the DC port may be connected to an opposite end of the high voltage capacitor; the controller is a first controller for the rectifier mode, the controller having at least one sensor for sensing current and/or voltage in the bi-directional rectifier/inverter and the sensor being connected to the gate inputs of two high voltage power switches, two intermediate low voltage power switches and two terminal low voltage power switches for operating the rectifier circuit in a boost mode, wherein the voltage of the high voltage capacitor is above the peak voltage of the AC input and the two high voltage power switches are controlled to turn on and off the frequency of the AC input and the two intermediate low voltage power switches and the two terminal low voltage power switches are switched to a redundant switching state in response to a measurement of the voltage present at the low voltage capacitor to maintain the low voltage capacitor at a predetermined fraction of the voltage required for the high voltage capacitor to maintain the high voltage capacitor at the required high voltage, the rectifier circuit acts as a five level active rectifier with low harmonics on the AC input to power and absorb power to the DC load; and the power converter further comprises a second controller for the inverter mode, the second controller being connected to the two high voltage power switches, the two intermediate low voltage power switches and the two terminal low voltage power switches and configured to generate and apply signal waveforms to the two high voltage power switches, the two intermediate low voltage power switches and the two terminal low voltage power switches, the signal waveforms comprising a first control signal for connecting the low voltage capacitor in series with the DC port and the AC port and being charged to a predetermined value proportional to the voltage of the DC port, and a second control signal for disconnecting the low voltage capacitor from the DC port and being connected in series with the AC port so as to discharge the low voltage capacitor.