TW201944685A - Electric vehicle battery charger - Google Patents

Abstract

A battery charger capable of receiving single-phase AC power and delivering both AC and DC power to an electric power storage battery in accordance to different embodiments disclosed herein. An AC input receives single phase power from an electrical entry, a switch is connected to the AC input further connecting it either to an AC output or to a power converter which responds to a charge voltage value and a desired charge current value to convert power to a variable DC voltage at a variable current not exceeding a desired charge current value for a DC load. The power converter has at least one high voltage capacitor for storing power at a voltage boosted above a peak voltage of the AC input.

Description

   Electric vehicle battery charger   

This application claims priority from US Provisional Patent Application No. 62 / 660,530, filed on April 20, 2018, the description of which is incorporated herein by reference.

The present invention relates to the field of battery charging systems, such as battery charging systems for electric vehicles. The invention also relates to the field of power converters, such as rectifiers that operate at residential voltage and power.

This section is intended to provide the background or context of the invention as set forth in the scope of the patent application. The description herein may include concepts that need to be achieved, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise stated herein, what is described in this section is not prior art to the specification and patentable scope of this application, and is not considered prior art by inclusion in this section.

Currently, an electric vehicle (E-V) typically includes a battery pack and a battery charging system. Battery packs typically require a direct current (D-C) input to charge the battery. To this end, an on-board charging circuit is provided that converts AC power typically used in a home into a DC input for a battery pack. In the case of charging commonly referred to as "level 1" and "level 2", battery charging systems have household or similar AC power that is converted to DC to supply the battery pack. Level 1 and level 2 charging mainly depends on the power supply and sometimes also the voltage.

"Level 3" charging generally refers to DC charging, which can involve DC current at high power, such as voltages and currents higher than 350V, resulting in charging power typically higher than 15kW and up to 160kW. Class 3 charging stations are commercial charging stations designed to charge EVs as quickly as possible. With current EV batteries, very fast charging can be achieved, reaching about 75% to 80% of the battery's charging capacity. For some electric vehicle batteries, it can be charged at high power, and 15% to 80% of the battery can be charged in 15 to 20 minutes. After that, charging is very slow, for example, it may take several hours to increase the charging level from 80% to 99%. Customers are generally encouraged to leave the charging station so that other customers can charge their vehicles. This fast charging facilitates the operation of commercial charging stations; however, experiencing such high power charging can shorten the life of some EV batteries. For example, in terms of battery life, it is preferable to allow 2 hours to charge from the battery 15% to 80% instead of 20 minutes.

The DC power source used for this charging is powered by a three-phase power source, which is typically used in commercial installations rather than residential. Three-phase alternating current can be effectively converted into direct current. Generally, such charging is not available in homes, where the available power is usually also limited to below 60kW. For example, in some places, residential power panels can be limited to 200A at 240V (RMS), bringing the total available power for all homes to 48kW. By using a main circuit breaker to provide such power limitation, a local distribution transformer of a certain size is generally used as an "overbooking" assumption, as an overload protection that statistically corresponds to too many houses using too much power. In addition, when starting from a single-phase AC current source, 3-level charging requires a rectifier circuit, which is usually not provided at home due to cost issues and other reasons.

Current residential car charging systems basically behave like high-powered devices, such as clothes dryers. In level 2 charging, the power is usually limited to about 7kW or lower, which is a load equivalent to a clothes dryer (30 amps at 240V is 7.2kW). The charging unit installed in the home connects the commercial AC power to the vehicle through the circuit breaker circuit, so that the vehicle's on-board AC to DC conversion circuit can charge the vehicle battery.

Most electric vehicles allow "fast" DC charging, in which case the AC to DC converter is external to the EV. The advantage of DC charging is not only that the charging power can be greater than the capacity of the AC-to-DC converter in the vehicle, but also that the conversion efficiency does not depend on the converter provided by the manufacturer when manufacturing the vehicle. If DC charging can be efficiently provided to a home, heavy and expensive Class 2 charging equipment can be omitted.

For level 2 power consumption, the probability that a vehicle charge will cause the residential power inlet or main circuit board to draw more than its allowed power budget (thus causing the main circuit breaker to trip and disconnecting the panel from the distribution transformer). However, when most home appliance panels add loads greater than 7 kW and last for several hours, the risk of exceeding the total power budget of the home appliance panel increases.

This patent application provides complementary improvements that can be applied individually or in combination. The first improvement involves an improved rectifier for DC charging. In one aspect, the improved rectifier has a high-voltage capacitor module that can be easily replaced within the charger. In another aspect, the charger includes a backplane and blade architecture that allows distribution on multiple lower power blade modules for AC to DC conversion, so that each blade module is used to provide less than about 5kVA, so that the blade module The combination of groups can provide power conversion of AC single-phase power to DC charging power output in excess of 10 kVA (and preferably in excess of 20 kVA). The second improvement relates to a battery charging system that allows power levels to be used for battery charging. If all non-rechargeable loads are connected to an inlet that uses its load at the same time, the power level will exceed the nominal budget of the power inlet. Therefore, according to the second improvement, time-based prediction of non-charged load power consumption is performed based on modeling and / or historical monitoring of non-charged load power consumption. A third improvement relates to a power converter having a charging power program module having a user input interface for receiving a user input defining a charging aggressiveness parameter, wherein the charging power program module is responsive to the charging aggressiveness parameter Control the current level over time. A fourth improvement relates to a socket-type connector for removing and replacing a high-voltage capacitor from a power converter. The fifth improvement relates to a power converter having a circuit capable of operating in a bidirectional state. In addition to providing a DC charging capability with an AC input as a rectifier, it can also convert voltage / current from DC to AC as an inverter, so , Provide AC output from DC battery of electric vehicle.

In some embodiments, the battery charger converts single-phase AC power and delivers DC power to a power storage battery. The AC input receives single-phase power from the power inlet, and a power converter is connected to the AC input and responds to the charging voltage value and the desired charging current value to convert the power to a variable DC voltage whose variable current does not exceed the charging of the desired DC load Current value. The power converter has at least one high-voltage capacitor for storing a boosted voltage at a voltage higher than the peak voltage of the AC input.

In some embodiments, the charger circuit can be operated in a bidirectional state, so that the voltage / current can be converted from AC to DC as a rectifier or from DC to AC as an inverter. Therefore, AC is provided from the DC battery of the electric vehicle Output.

In one aspect of the present disclosure, the charger circuit can only function as a rectifier. By replacing two high-voltage switches between the first terminal of the high-voltage capacitor connected to the charger circuit and the corresponding opposite ends, the two poles Body, which converts AC voltage to DC in a unidirectional manner as a unidirectional charger.

Here, the battery charger converter operating in the rectifier or inverter mode may be referred to as a battery charger rectifier or a battery charger inverter, respectively.

In some embodiments, the battery charger disclosed herein has a housing for an AC input (which is used to receive single-phase power from a power inlet), an AC output, and a DC output, wherein a switch is connected between the AC input and the AC output. The switch is also connected to a backplane having one or more modular connectors adapted to receive one or more DC power converter modules. In AC mode, the switch is closed and the AC input is connected to the AC output to provide AC current to the power storage battery. In DC mode, the switch is turned off and the AC input is connected to the DC power converter assembly to provide DC current to the DC output.

In one embodiment, the charger has a module connector that is suitable for receiving one or more DC power converter modules, but does not have the DC originally provided in the housing to provide the user with a 2-level AC EV battery charger Power converter module. The DC power converter module can be added to the charger at a later time to upgrade to a level 3 DC EV charger.

In one other aspect, the present invention provides a portable DC charging unit for an electric vehicle. The DC portable unit includes a housing having a connector back plate having a plurality of sockets for receiving at least one module including a battery rectifier circuit, an AC input receiving an AC current from an AC power source, And a DC output connected to the vehicle via a DC cable.

In another broad aspect, the present disclosure provides a power converter connected to an AC input that converts power from the AC input to DC, including at least one high-voltage capacitor for increasing the voltage at a peak voltage higher than the AC input. The voltage stored in the voltage, rectifier circuit. The rectifier includes an inductor connected in series with the AC input, a low voltage capacitor, and two diodes or optionally two high voltage switches connected between the first AC input terminal and the opposite end of the high voltage capacitor, two The intermediate low voltage power switch is connected between the opposite end of the high voltage capacitor and the opposite end of the low voltage capacitor, and the two terminals of the low voltage power switch are connected between the opposite end of the low voltage capacitor and the second AC terminal, where the DC load Can be connected to the opposite end of a high voltage capacitor. The power converter includes a controller having at least one sensor for sensing current and / or voltage in the rectifier circuit and connected to two intermediate low-voltage power switches and two terminal low-voltage power switches. Gate input.

In some embodiments, the controller is operable to cause the rectifier circuit to operate in boost mode, where 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 voltages The power switch is switched in a redundant switching state in response to the measurement of the voltage present at the low voltage capacitor to maintain the low voltage capacitor at a predetermined portion of the desired voltage of the high voltage capacitor, thereby keeping the high voltage capacitor at the required high voltage The rectifier circuit provides a DC load and absorbs power to form a five-stage active rectifier with low harmonics at the AC input.

In some embodiments, the power converter has a bidirectional rectifier / inverter circuit and two controllers instead of a rectifier circuit, rather than a controller capable of bidirectional operation as a rectifier and an inverter. The bidirectional rectifier / inverter circuit includes an inductor connected in series with the AC port, a low voltage capacitor, two high voltage power switches connected between the first AC terminal and the opposite end of the high voltage capacitor, and two intermediate low voltage power supplies. The switch is connected between the opposite end of the high-voltage capacitor and the opposite end of the low-voltage capacitor, and the two-terminal low-voltage power switch connected between the opposite end of the low-voltage capacitor and the second AC terminal; wherein the DC port can be connected To the opposite ends of the high voltage capacitor. The power converter includes a first controller for a rectifier mode having at least one sensor for sensing current and / or voltage in a bidirectional rectifier / inverter and connected to two high-voltage power switches. Gate input, two intermediate low-voltage power switches, and two-terminal low-voltage power switches for the rectifier circuit to work in boost mode, where the voltage of the high-voltage capacitor is higher than the peak voltage of the AC input and controls the two high-voltage The voltage power switch is turned 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 switch are switched in a redundant switching state in response to the measurement of the voltage present at the low-voltage capacitor so that The low-voltage capacitor is held at a predetermined portion of the desired voltage of the high-voltage capacitor, thereby keeping the high-voltage capacitor at the required high voltage. The rectifier circuit provides a DC load and absorbs power to form a five-stage active rectifier. Low harmonics. The power converter has a second controller for inverter mode, which is connected to two high-voltage power switches, two intermediate low-voltage power switches, and two terminal low-voltage power switches, and is configured to generate and apply Signal waveforms for two high-voltage power switches, two intermediate low-voltage power switches, and two-terminal low-voltage power switches, including a first control signal for connecting a low-voltage capacitor to a DC port and an AC port in series and charging To a predetermined value DC port proportional to the voltage, and the second control signal is used to disconnect the low voltage capacitor from the DC port and connect it in series with the AC port to discharge the low voltage capacitor.

In one aspect, the present disclosure provides a battery charger for converting single-phase AC power and delivering DC power to a power storage battery. The charger includes an AC input for receiving single-phase power from a power inlet, a battery charge controller interface for connecting to a power storage battery and receiving a charging voltage value and a desired charging current value, a power converter connected to the AC input, and It is responsive to the charging voltage value and the desired charging current value to convert the power from the AC input into a variable voltage according to the charging voltage value and a variable current that does not exceed the desired charging current value under the condition of DC load. The DC power at the DC output of the power converter includes at least one high voltage capacitor for storing power at a boosted voltage higher than the peak voltage of the AC input. The charger is also characterized by one of the following:

-In some embodiments, the power converter includes an inlet power sensor and a power draw increase prediction module for measuring power drawn from the power inlet from its power distribution transformer While the power draw increase prediction module has an input for receiving the value of the drawn power and an output that provides the largest possible jump in power drawn at the power inlet, the power converter is configured to limit the power converter output Current level to prevent the power drawn at the power inlet from exceeding a predetermined limit when the maximum possible jump in power drawn occurs;

-In some embodiments, the power converter includes a charging power program module having a user input interface for receiving user input defining charging aggressiveness parameters, wherein the charging power program module is controlled over time in response to the charging aggressiveness parameter Current level.

-In some embodiments, the charger includes a socket-type connector for removing and replacing a high voltage capacitor from the power converter.

-In some embodiments, the power converter includes a rectifier circuit including an inductor connected in series with the AC input, a low voltage capacitor, and two high voltages connected between the first AC input terminal and the opposite ends of the high voltage capacitor Power switch, two intermediate low voltage power switches connected between the opposite end of the high voltage capacitor and the opposite end of the low voltage capacitor, and two terminals connected between the opposite end of the low voltage capacitor and the second AC terminal are low Voltage power switch where a DC load can be connected to the opposite end of a high voltage capacitor. The power converter includes a controller having at least one sensor for sensing current and / or voltage in the rectifier circuit and connected to two high-voltage power switches, two intermediate low-voltage power switches and The gate input of the two-terminal low-voltage power switch is used to make the rectifier circuit work in boost mode, where the voltage of the high-voltage capacitor is higher than the peak voltage of the AC input, and the two high-voltage power switches are controlled by the AC input. Frequency is on and off, two intermediate low-voltage power switches and two-terminal low-voltage power switches switch in redundant switching state in response to measurement of the voltage present on the low-voltage capacitor in order to keep the low-voltage capacitor at a high level A predetermined portion of the required voltage of the voltage capacitor, and thus maintaining the high voltage capacitor at the required high voltage, and a rectifier circuit that provides a DC load and absorbs power as a five-level quasi-active rectifier with low harmonics on the AC input, And a buck converter circuit for converting the direct current from the opposite end of the high voltage capacitor to a lower charge DC output voltage set by the electrical voltage value.

In some embodiments, the charger is characterized by a power converter that includes both: a power inlet power sensor and a power draw increase prediction module, the power inlet power sensor is used to measure The power drawn at the power inlet, and the power draw increase prediction module has an input for receiving the value of the power drawn and an output that provides the largest possible jump in the power drawn at the power inlet. The power converter is configured to Limiting the level of current output by the power converter to prevent the power drawn at the power inlet from exceeding a predetermined limit when the largest possible jump in the drawn power occurs; and a) a rectifier circuit including an inductor connected in series with the AC input , A low-voltage capacitor, two high-voltage power switches connected between the first AC input terminal and the opposite end of the high-voltage capacitor, connected between two middles between the opposite end of the high-voltage capacitor and the opposite end of the low-voltage capacitor Low voltage power switch, and connected between the opposite end of the low voltage capacitor and the second AC terminal A two-terminal low-voltage power switch between which a DC load can be connected to the opposite end of the high-voltage capacitor; b) a controller having at least one sensor for sensing the current in the rectifier circuit and / Or voltage and 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 the rectifier circuit to operate in boost mode, where the high-voltage capacitors The voltage is higher than the peak voltage of the AC input, and two high-voltage power switches are controlled to turn on and off at the frequency of the AC input. Two intermediate low-voltage power switches and two terminal low-voltage power switches respond to the low-voltage capacitor. The measurement of the existing voltage is switched in a redundant switching state in order to keep the low-voltage capacitor at a predetermined portion of the required voltage of the high-voltage capacitor, and therefore to keep the high-voltage capacitor at the required high voltage, and to provide a DC load and Power-absorbing rectifier circuit as a five-bit quasi-active rectifier with low harmonics on the AC input; and c) step-down conversion And a converter circuit for converting the direct current from the opposite end of the high-voltage capacitor into a lower direct-current output voltage set by a charging voltage value.

In some embodiments, the charger has a network interface for receiving user input, including a remote device user interface connected to the network interface.

In one embodiment, the power converter includes a charging power program module, and the charging aggressiveness parameter defines an upper limit of a charging current for charging the vehicle.

In one example, the charging power program module records a history of the charging current so that an evaluation of battery degradation can be performed.

In some embodiments, the charger is characterized in that the power converter includes a power inlet power sensor and a power draw increase prediction module for measuring the power drawn by the power inlet from its power distribution transformer While the power draw increase prediction module has an input for receiving the value of the drawn power and an output that provides the value of the largest possible power jump in the power drawn at the power inlet, the power converter is configured to limit the The level of the output current to prevent the power drawn at the power inlet from exceeding a predetermined limit when the largest possible jump in the drawn power occurs, including a disconnectable load switch; wherein the power draw increase prediction module is connected to the The disconnectable load switch is used for temporarily disconnecting at least one disconnectable load connectable to the disconnectable load switch when a danger of exceeding the predetermined limit is caused by the approaching maximum possible jump value in the drawn power. , The power draw increase prediction module is configured to be determined when the power draw increase prediction module is determined The predetermined limit is too close to risk has subsided, reconnecting said load is disconnected.

The claimed systems, methods, and broader technologies are described herein and are described in detail below.

100‧‧‧ Battery Charger Converter

105‧‧‧AC input

110‧‧‧Inductive filter

115‧‧‧5 level topological circuit

116‧‧‧Auxiliary circuit

120‧‧‧High-voltage capacitor

125‧‧‧low voltage capacitor

130a, 130b‧‧‧High Voltage Power Switch

132a, 132b‧‧‧diodes

135‧‧‧First terminal 1

140a, 140b ‧‧‧ middle low voltage power switch

145a, 145b‧‧‧

150a, 150b‧‧‧terminal low voltage power switch

155a, 155b‧‧‧opposite ends

160‧‧‧Second input terminal

200‧‧‧ topology, circuit

202‧‧‧AC load

205, 210‧‧‧ current path

206, 208‧‧‧ components

305‧‧‧Voltage balance

310‧‧‧Modulator

315‧‧‧state selection circuit

320‧‧‧Reference signal

325‧‧‧Pulse generator module

340‧‧‧Switch unit

405‧‧‧Module

410‧‧‧controller

810‧‧‧Battery Management System

815‧‧‧Charging cable

820‧‧‧Battery Charge Controller Interface

830‧‧‧Computer

840‧‧‧back

902‧‧‧Interface

904‧‧‧Recording module

906‧‧‧Power Budget Controller

908‧‧‧Available power predictor

910‧‧‧Charge Power Program Module

1100‧‧‧AC charging blade

1102‧‧‧Overcharge prevention module

1200‧‧‧ Portable DC Charging Unit

1202‧‧‧shell

1204‧‧‧AC input

1206, 1210‧‧‧ cable

1208‧‧‧DC output

1302‧‧‧ Connector Backplane

1304‧‧‧Socket

1306‧‧‧ Blade Module

S1 ~ S7‧‧‧‧Switch

The embodiments of the present application will be better understood with reference to the following drawings: Figure 1 is a schematic diagram of the physical installation of a household electric vehicle charging system, which includes a pole top transformer, a load sensor and a main circuit breaker panel 240V AC power line between residential power inlet, panel and charger, charging cable extending between charger and electric vehicle (EV), with CAN bus connection between electric vehicle and charger; Figure 2A shows A circuit diagram of a battery charger converter according to a specific embodiment, the battery charger converter has a 5-level topology circuit operating in a rectifier mode.

Figure 2B shows the circuit diagram of the 5-level topology of the battery charger of Figure 2A, showing the connection in a switch configuration called "State 2"; Figure 2C shows the battery of Figure 2A Circuit diagram of a 5-level topology of a charger, showing the connection in a switch configuration called "state 3"; Figure 2D shows a 5-level topology of a unidirectional / rectifier charger according to a specific embodiment Figure 2E shows a circuit diagram of a battery charger converter with a 5-level topology circuit operating in inverter mode according to one embodiment; Figure 3A shows a rectifier mode with Figure 1 Block diagram of a voltage-balanced modulator of a battery charger converter operating under the condition; the signal diagram shown in FIG. 3B shows the 4-carrier pulse width modulation technology used in the modulator of FIG. 3A; Fig. 3C shows a circuit diagram showing the components of the controller of the battery charger converter of Fig. 1 operating in rectifier mode; Fig. 3D shows the operation of the inverter in inverter mode showing Fig. 2E Battery charger converter controller Figure 3E shows the logic elements of the modulator and state selection circuit to provide 8 signals indicating the various states using voltage and current feedback; Figure 4 shows the battery charger converter of Figure 1 1 A block diagram of operation in a rectifier mode including a controller circuit; a signal diagram shown in FIG. 5 shows a steady state result of the battery charger converter of FIG. 1 operating in rectifier mode at 1 kW operation.

Figure 6 shows a screenshot of the power analyzer showing some parameters of the battery charger converter of Figure 1 operating in rectifier mode measured by the power analyzer; Figure 7 shows the Signal diagram of battery charger converter performance, which works in rectifier mode during a 50% change in DC load; Figure 8A is a block diagram showing a modular converter battery charging system; Figure 8B is a diagram showing AC A block diagram of a charger for a battery charging system with a modular converter; FIG. 8C is a block diagram showing an embodiment of a charger having a switch connected to a back plate providing an AC output; FIG. 8D is a FIG. 8C is a block diagram of an embodiment in which switches are replaced by a modular converter battery charging system; FIG. 9 is a block diagram showing a charging power budget controller; and FIG. 10 is a power converter module according to an embodiment Figure 11 is a schematic diagram of an AC charging module according to an embodiment; Figure 12 is a schematic diagram of the physical installation of a portable EV charging system, which includes a delay between a charger and an electric vehicle (EV). An extended charging cable with a battery rectifier unit between the EV and the charger; Figure 13 is a block diagram showing the portable EV charging system in Figure 12; Figure 14A is for storing a receiver with a receiver according to a specific embodiment And FIG. 14B is a schematic diagram of accessories for storing a portable EV charging system with a receiver according to a specific embodiment.

Reference throughout this specification to "one embodiment", "multiple embodiments", 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, the phrases "in one embodiment", "in multiple embodiments", and similar language that appear throughout this specification may, but 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. Accordingly, the invention is intended to cover modifications and variations of the invention that fall within the scope of the appended patent applications and their equivalents. Reference will now be made in detail to the preferred embodiments of the present invention.

Throughout the application, the term "EV secondary charger" refers to a single-phase AC EV charger, and the term "EV three-stage charger" refers to a single-phase DC EV charger.

Figure 1 shows the physical background of the embodiment, in which separated single-phase mains power is transmitted from a transformer at the top of a utility pole, which is the most common type of power transmission in North America. Transformers usually receive 14.4kV or 25kV single-phase power from the distribution line, and the transformer can handle power from about 50kVA to 167kVA, which is transmitted as a split-phase 240V AC to a small number of homes or power inlets. Each power inlet is usually configured to handle 100A to 200A power at 240V AC, that is, about 24kVA to 48kVA (generally assuming 1kVA is equivalent to 1kW).

It should be understood that the embodiments are not limited to a separated single-phase 240V AC power system, and the embodiments disclosed herein may be applicable to a power network in use, which is any existing single-phase AC voltage delivered to the power inlet of a home or business.

The power inlet usually includes a usage meter, a main circuit breaker with a rating corresponding to the total allowable load (e.g. 100A or 200A), and a panel with a circuit breaker for each household circuit, which can be supplied with 240V AC power or 120V AC power divided by 240V AC input. Although most circuit breakers have a capacity between 15A and 30A, some can be lower (that is, 10A), while some may be larger, such as 40A, for large appliances. In some countries, the capacity of the power inlet is low, such as 40A to 60A, and in countries with 240V AC in all household circuits, the power supply is not phase-separated, but conventional single-phase 240V AC (the voltage level used may be different (From about 100V to 250V).

As shown in Figure 1, the charger is connected to the circuit breaker of the main panel through a circuit breaker with a larger rated current, such as 40A to 80A, although the disclosed charger can consume more than 100A if needed. The need for charger-specific circuit breakers is determined by power regulations. The cable connecting the charger to the panel is used for this high current. The connection to the power panel can be directly fixed wiring, or a high-voltage outlet can be installed and connected to the power panel so that the charger is connected to the panel using cables and plugs, for example, similar to those used in ovens or clothes dryers Cables and plugs. The charger is shown connected to a single load sensor that senses the load of the entire panel, including the charger. As known in the art, the charger cable may be a conventional charger cable and plug.

FIG. 2A illustrates a battery charger converter 100 for an electric vehicle according to a specific embodiment. This circuit uses a 5-level package U-shaped unit topology and provides an active rectifier with power factor correction. Compared to other types of converters, this charger has several noteworthy advantages, with boost mode operation, allowing ultra-ac peak output while reducing or eliminating input-side current harmonics.

The battery charger converter 100 includes an AC input 105, an inductive filter 110 connected in series with the AC input 105, and a 5-level level topology circuit 115.

In this non-limiting example, the inductive filter 110 is a 2.5 mH inductor. For a typical power delivery range of 1 to 3 kW (corresponding to all charging states during full power and partial power), a 1 mH line inductor is provided that works well with existing standards to produce good results. For higher power ranges, the inductance can be reduced; for example, for high wattage (eg, greater than 2 kW, and preferably greater than 3 kW, and more preferably about 5 kW) power levels, the inductive filter 110 may instead use a 500 μH inductor . Conveniently, this design achieves the small geometry of the entire battery charger converter 100, due in part to the small size of the inductive filter 110. The inductive filter 110 may vary depending on the design selected for the application, rated power, utility voltage harmonics, switching frequency, and the like. Although the simplest such filter is a single inductor, in alternative embodiments, the inductive filter 110 may include a combination of an inductor (s) and a capacitor (s), for example, (e.g., 2MH) inductor is connected to (for example, 30 μF) capacitor, which itself is grounded. The choice of filter will affect the overall size and loss of the design. Larger filters will increase the size of the overall design and will usually result in more losses.

The level 5 circuit includes a high-voltage capacitor 120, at least one low-voltage capacitor 125, two high-voltage power switches 130a, 130b, and connected to the opposite terminals 145a, 145b of the first terminal 135 and the high-voltage capacitor 120, two Middle low-voltage power switches 140a, 140b, each connected between a corresponding one of two opposite ends 145a, 145b of the high-voltage capacitor 120 and a corresponding opposite end 155a, 155b of the low-voltage capacitor 125, and two The terminal low-voltage power switches 150a, 150b are each connected between the second input terminal 160 and a corresponding one of the opposite ends 155a, 155b of the low-voltage capacitor 125.

The capacitor is so named because the high voltage capacitor 120 has a higher voltage across its ends than the low voltage capacitor 125 in use. In this particular example, the voltage V _o across the high voltage capacitor 120 is approximately twice the voltage V _C across the low voltage capacitor 125. In this embodiment, the high-voltage capacitor 120 and the low-voltage capacitor 125 are different devices. The high-voltage capacitor 120 is a 2 mF capacitor and the low-voltage capacitor is a 50 μF capacitor. For a typical 1 to 3 kW power output range (during all states of charge from full power to partial power), a combination of a 2 mF capacitor for high voltage capacitor 120 and a 100 μF capacitor for low voltage capacitor 125 gives good results , In line with existing standards. It has been found that this is effective when using a sample time of 20 μs for voltage balancing. For 5kW power devices, a combination of a 4mF capacitor for high-voltage capacitor 120 and a 200μF capacitor for low-voltage capacitor 125 may be appropriate, but smaller capacitors can be used by increasing the sampling speed of the balanced voltage to achieve More accurate voltage balance calculation. This can be achieved by using faster microprocessors. Each capacitor may be an electrolytic capacitor or a film capacitor, but in this example, the low-voltage capacitor 125 not connected to the load is a high-lifetime film capacitor. The high voltage capacitor 120 will have a shorter life and may be the cause of a circuit failure. In the embodiment shown in FIG. 10, the high-voltage capacitor is therefore provided as a replaceable component, as will be described further with reference to FIG.

Naturally, it is more economical to use a capacitor having characteristics that do not exceed its requirements, but there is no prohibition on using the same capacitor for the high voltage capacitor 120 and the low voltage capacitor 125, although the low voltage capacitor 125 may be excessively wasted in this case .

The intermediate low-voltage power switches 140a and 140b and the terminal low-voltage power switches 150a and 150b together constitute an auxiliary power switch. As with capacitors, the high-voltage power switches 130a, 130b and the low-voltage power switches are so called because the high-voltage power switches 130a, 130b have a higher voltage in use than the auxiliary power switches. Moreover, according to the present design, the low-voltage power switch is a high-frequency power switch, and the high-voltage power switches 130a and 130b are low-frequency switches. Also, they are so called because in use, high frequency switches operate / switch at a higher frequency than low frequency switches. In fact, the same switches can be used as long as they are suitable for applying the highest frequency of a high-frequency switch and they are suitable for applying a high voltage to a high-voltage switch. However, it is preferred to provide a switch that is only suitable for its intended use in order to reduce costs and possible size and weight. Switches can be all FET, JFET, IGBT and MOSFET types.

The low-voltage capacitor 125 of the 5-level level circuit 115 can be considered as an auxiliary capacitor, which together with the auxiliary power switch constitutes the auxiliary circuit 116 of the 5-level level circuit 115. As described herein, in alternative embodiments, additional auxiliary capacitor (s) and one (or more) pairs of switches may be provided in the auxiliary circuit 116.

The switching states of the 5-level level circuit 115 have been studied to show those redundancy to help balance the voltage of the auxiliary capacitor. Capacitor voltage balancing allows a 5-level voltage level to be generated at the input of the rectifier and reduces voltage harmonics that directly affect the current harmonic content. Adjust the output voltage to supply the DC load. Here, experimental results are provided to demonstrate the dynamic performance of the proposed rectifier operating at a unit power factor and to obtain low harmonic AC current from the power supply.

As shown in FIG. 2A, the 5-level level circuit 115 operates in a rectification mode with only 6 switches, which generate 5 voltage levels. An advantageous feature of this configuration is that the redundant switching state facilitates voltage balance between the DC power paths. The 5-level level rectifier proposed in this disclosure operates at unit power factor and eliminates input AC current harmonics due to operation in boost mode. The low total harmonic distortion (THD) level 5 voltage waveform of the level 5 rectifier directly affects line current harmonics, so the inductive filter can be smaller than the level 2 rectifier to reduce the size of the product. Since the auxiliary DC capacitor voltage can be balanced only by redundant switching states, the voltage / current adjustment of the 5-level rectifier is the same as the full-bridge voltage with a single output DC terminal, which can be accomplished by cascading PI controllers.

The 5-level rectifier configuration and switching state will now be discussed. A switching technique based on voltage balancing is provided here. Regarding the described design, actual tests have been performed under different conditions such as load changes, major changes in alternating current, and these tests have shown good dynamic performance of the battery charger converter 100 in the rectifier mode.

The 5-level level circuit 115 has two direct current paths. The main DC power path includes a high voltage capacitor 120 that is voltage regulated to provide a DC load. The voltage across the high-voltage capacitor 120 is represented herein as V _o . The secondary direct current path includes an auxiliary capacitor (low-voltage capacitor 125). The voltage across the low-voltage capacitor 125 is represented here as V _C. V _C has a half of the voltage amplitude of the main terminal V _o and an input voltage (V _in ) between the first and second terminals for forming the rectifier as a quasi-sine wave of level 5. Therefore, V _C = E, V _o = 2E, and the 5 voltage levels include 0, ± E, ± 2E.

Here, operating in boost mode means that the output DC voltage is higher than the input AC peak. In this example:

Based on the peak value of the AC grid, the DC voltage was chosen to be 200V. Now that V _C is half of V _o , we have: V _o = 200V → V _C = 100V

To this end, the output terminal voltage V _o is adjusted to 200V to be delivered to a DC load, which in this example is an EV battery pack. In addition, the auxiliary capacitor voltage V _C is balanced at 100 V so as to generate a level 5 voltage waveform as V _in .

Based on the voltages selected above, two high-voltage power switches 130a, 130b are selected to withstand 200V. The auxiliary power switch is connected to the high voltage power switches 130a, 130b at only about half the voltage, which is 100V in this example.

Table 1 shows the switching states of the 5-level level circuit 115. Each pair of switches, in this example, includes a pair of high voltage power switches 130a, 130b, a pair of intermediate low voltage power switches 140a, 140b, and a pair of terminal low voltage power switches 150a, 150b, which are complementary, meaning that when one When open, the other is closed and vice versa.

It can be observed that based on each configuration of the switch, a path is provided to allow current to flow through the converter, and a voltage level is generated at the input, which together form a 5-level voltage waveform. This waveform has lower total harmonic distortion (THD) and directly affects the current content of the drawn harmonics (if there is a harmonic in the voltage waveform, it will also inject the current waveform. The low harmonic voltage waveform results in a low harmonic current waveform) . Compared to the larger filters of a typical 2-stage converter, the naturally reduced amount of THD allows smaller filters to be used in AC lines with acceptable performance.

As can be seen from Table 1, the high-voltage power switches 130a, 130b are actually switched only twice per cycle. However, the auxiliary power switch can be switched at a higher frequency, for example, to switch between redundant states (e.g., states 2 and 3) multiple times before moving to the next non-redundant state (e.g., state 4). In some embodiments, the low voltage power switch can be switched at a high frequency of at least or greater than 1 kHz, for example, greater than 10 kHz. In this particular example, the switching frequency may be 48 kHz.

The voltage balance for the battery charger rectifier 100 will now be described. It can be seen from Table 1 that there is some redundancy between the switching states, that is, there are switching states that cause the same V _in voltage, such as states 2 and 3 or states 6 and 7. Since the main output is V _o , which is controlled by an external PI controller, the redundant switching state can help in several ways. One benefit of the redundant switching state is to reduce the voltage error of _Vo , which reduces the burden on the external controller. In addition, the balanced auxiliary capacitor voltage V _C allows five identical voltage levels to be provided in order to produce a low THD quasi-sinusoidal waveform.

In Figures 2B and 2C, the current paths 205, 210 for redundant states 2 and 3 are shown, respectively, to better illustrate the effect of the redundant switching state on the DC path voltage balance. It is assumed that the DC path polarity is as shown in the figure. They can be charged or discharged based on the current sign. In state 2, assuming that the current is positive, the high-voltage capacitor 120 is charged, and the low-voltage capacitor 125 is discharged due to its polarity reversal. Therefore, V _o and V _C increase and decrease, respectively. However, in state 3, the low voltage capacitor 125 will be charged in state 3 by a positive current. If the current sign is negative, these states have the opposite effect. It should also be noted that as long as it is not connected through an AC power source, V _o will decrease due to load discharge.

Table 2 similarly shows the impact of each switching state on the high-voltage capacitor 120 and the low-voltage capacitor 125, which provides useful information for design-related voltage balancing techniques.

Since the proposed converter can be grid-connected and the associated controller already includes a current sensor, it can be avoided to have additional sensors and associated costs. Feedback signals from the same line current sensor can be used for the voltage balancing technique. Two voltage sensors can be used as DC voltage feedback, and the switching technique can include multi-carrier PWM controlled by the voltage effects listed in Table 2. Switching technology selects redundant switching states based on feedback received from current and voltage sensors.

As shown in FIG. 2D, in some embodiments, the high-voltage power switches 130a and 130b may be replaced by two diodes 132a and 132b, and a 5-level unidirectional rectifier is provided, which can only convert AC voltage to DC as One-way charger. Those skilled in the art will understand that using a 5-level unidirectional rectifier will not affect the working mode of the present invention and can be used as an alternative to the 5-level circuit in all the embodiments disclosed herein.

In some embodiments, the 5-level circuit can be operated in a bi-directional state. This means that it can convert voltage / current from AC to DC in rectifier mode as shown in Figure 2A, or from DC to AC in inverter mode as shown in Figure 2E. When operating in rectifier mode, the invention has a DC output.

In inverter mode, a high voltage capacitor (V _o ) is connected to a DC source, such as an isolated DC power source, a battery or a solar panel. A level 5 circuit can generate AC voltage / current from these DC inputs. This AC current can be injected into the power grid as a grid-connected operation mode, or it can be used as a power source to supply common AC loads. Inverter mode can be used in the car-to-grid approach, where car batteries can involve peak load distribution of utilities or supply some critical loads in the home when there is no power.

Referring to FIG. 2E, a topology 200 of a 5-level power converter for operation in an inverter mode is shown according to one embodiment. The AC load 202 is connected between the first terminal 135 and the second terminal 160, which corresponds to a unique node in a circuit to which only the switching element is connected. The voltage generated between the first terminal 135 and the second terminal 160 is an inverter output voltage (V), which is schematically a 5-level level pulse width modulation (PWM) waveform.

Although the use of PWM is mentioned herein when describing the control strategy implemented for the proposed 5-level level inverter, it should be understood that other control techniques may be used. Examples include, but are not limited to, selective harmonic cancellation PWM and optimized harmonic step waveforms. PWM technologies such as shift PWM technology, sinusoidal natural PWM technology, and programmed PWM technology can be used. Open-loop and closed-loop technologies can be used. Examples of open loop technologies are Space Vector and Sigma Delta technologies. Examples of closed loop technology are hysteretic current controllers, linear current controllers, DDB current controllers and optimized current controllers.

In the illustrated embodiment, the 5-level level inverter circuit 200 can generate five different output voltages using various combinations of switches in the on / off state, which will be discussed further below. The six switches 130a, 130b, 140a, 140b, 150a, and 150b can be implemented using a bipolar junction transistor (BJT). Parasitic diodes that are implicitly present due to the nature of the BJT are shown to indicate the biasing direction of the transistor, ie, reverse bias, so that the transistor behaves as a switch rather than a short circuit. It should be noted that alternative ways of implementing the switch are possible. Such as gate fluid (thyristor), such as gate can shut off gate fluid (GTO) or integrated gate commutation gate fluid (IGCT), relay, isolated gate bipolar transistor (IGBT), metal oxide semiconductor field effect Crystal (MOSFET) or any other suitable controllable switch.

The circuit 200 includes elements such as 206 and 208, which are connected in a closed loop such that each element 206, 208 is connected to four of the switching elements 130a, 130b, 140a, 140b, 150a, and 150b. Element 206 is illustratively a direct current source (ie, a battery, a solar panel, etc.), while element 208 is a secondary voltage source, such as an energy storage device for a capacitor (as shown) or a combination of capacitors (not shown), Used as auxiliary power.

Although the circuit 200 is shown as including one element 208 to implement a 5-level level inverter, it should be understood that additional elements 208 may be provided to implement more levels at the output of the inverter, as will be discussed further below .

FIG. 3A schematically illustrates a modulator incorporating a voltage balancing technology, which has a voltage balancing 305. As shown, in this example, a modulator 310 that provides a 5-level PWM is used. In this example, a 4-carrier PWM technique is used to modulate the reference signal 320, as shown in FIG. 3B. Its reference signal 320 is provided by the controller described below. The output of the modulator 310 is provided to a state selection circuit 315, which enforces the logic of Tables 1 and 2 to generate an input to a switch, which is sent to S1, S2, and S3 in the form of a signal, and these The inverted (opposite state) forms of the signals are sent to S4, S5, and S6, respectively. The state selection circuit 315 provides a fast voltage balancing process integrated into the switching technology, whereby it is expected that small-sized capacitors will be suitable for auxiliary capacitors. A schematic diagram of the algorithm used is shown in Figure 3C, which shows the logic elements of the modulator 310 and the state selection circuit 315 to provide eight signals indicating various states using voltage feedback. Figure 3E shows the same logic element when using current and voltage feedback.

Alternatively, FIG. 3D illustrates the logic elements of the modulator 310 and the state selection circuit 315 to provide 5 signals indicating the respective states without using any feedback.

The pulse generator module 325 then uses these signals to generate a pulse output to the switch. In one embodiment, the pulse generator 325 may be a switch table that can be programmed by a microcontroller.

Those skilled in the art will understand that digital switching signals may pass through the gate driver before reaching the switch.

In Fig. 3A, the use of voltage feedback in a voltage balancing component is shown. However, the voltage balancing unit may use voltage or current feedback. When both are used, the capacitor voltage can be balanced more stably.

Figure 3E shows a schematic diagram of an algorithm that can be used, which shows the logic elements of the modulator 310 and the state selection circuit 315 to provide eight signals indicating various states using voltage and current feedback, as shown in the figure. . This arrangement has relatively good performance.

In one embodiment, the module 315 determines the best choice for the number of switching states (see Table 1), and then sends it to the module 325. Switching pulses (S1 to S6) are generated based on the status number. For example, if module 315 determines state 1, according to Table 1, S1, S5, and S6 will be ON, and S2, S3, and S4 will be OFF correspondingly.

In one embodiment, the reference signal 320 in FIG. 4 may be considered as V _ref in FIG. 3.

Controller 410 for the system. The system may employ a cascaded proportional-integral (PU) controller, which will now be described. As described above, since the auxiliary capacitor voltage is balanced by the switching state, this exemplary configuration can be used as a single DC source inverter. Although some proposed topologies have been proposed for rectification using two DC capacitors, in this embodiment, the auxiliary capacitor is voltage controlled by the designed switching technology and does not require any additional voltage regulators. Therefore, we can use only an external voltage controller to stabilize the output DC terminal to the required level, which is 200V in this example. As a result, a simple cascaded PI controller can be used to regulate the DC voltage of the output, and to control the input current and synchronize it with the grid voltage to ensure the power factor correction (PFC) operation of the rectifier. The controller 410 regulates V _o and i _s, in response to an input from the battery management system (BMS), for example, may be provided on the EV.

In some examples of the present disclosure, the controller (module 405) shown in FIG. 4 includes a current loop and a voltage loop. The voltage loop is responsible for stabilizing the C1 voltage at the reference level. A proportional-integral (PI) controller minimizes voltage errors and its output enters the current loop as a current reference. The current loop samples from the grid voltage (vs) and sends the current error to another PI controller to adjust the phase shift between vs and is. (PFC with zero-degree phase shift is preferred, but it can be adjusted to any value with the reactive power exchange of the grid.) Since the two loops are connected in series, it is called a linear cascaded PI controller. The output of the controller as a reference signal (unit 320) enters the modulation unit 305 to generate switching pulses based on redundancy to balance the second capacitor voltage (C2).

Those skilled in the art will understand that other types of controllers known in the art may be used instead, such as non-linear controllers, model predictions, sliding modes, or other suitable controllers known in the art.

The controller may be provided by a processor-based microcontroller having control software that uses inputs from the sensors and provides gate control signal outputs for digital systems following the logic described herein. The controller may also include analog circuits using active and passive components. The analog circuit can get some feedback from the system voltage and current and send the reference signal to the modulator.

FIG. 3D shows a schematic diagram of an algorithm used in some embodiments of the present disclosure. The state selection circuit 315 provides eight signals indicating each state, and does not use a sensor to transmit signals indicating each state ("No sense Tester "). In addition, FIG. 3D illustrates a logic element of the switching unit 340 used in the embodiment of the present invention when the charger converter operates in the inverter mode. Those skilled in the art will understand that the converter can be suitable for the switching pulse generation and the voltage balance of the auxiliary capacitor (low capacitance) in the 5-stage configuration. When it works in the rectifier mode and the converter mode, it is not limited to one type. Operating mode.

Referring to FIG. 10, it can be understood that the controller 410 also controls a DC-to-DC buck or boost converter in response to a desired output DC voltage requested by the BMS. In Figure 10, this is a simple buck or boost converter, controlled by switch S7, using the feedback of the DC output voltage measured by the sensor.

Those skilled in the art will understand that any type of buck or boost or buck-boost converter known in the art can be used without affecting the way the invention works. Two important topologies are called buck-boost converters, which can produce a range of output voltages, ranging from much larger (absolute amplitude) than the input voltage to almost zero.

The first topology is an inverting topology, where the polarity of the output voltage is opposite to the polarity of the input voltage. This is a switch-mode power supply with a circuit topology similar to that of a boost converter and a buck converter. The output voltage can be adjusted according to the duty cycle of the switching transistor.

The second topology is a combination of a buck (down) converter and a boost (rise) converter, where the output voltage is usually the same polarity as the input and can be lower or higher than the input. This non-inverting buck-boost converter can use a single inductor for buck-inductor mode and boost-inductor mode, using switches instead of diodes.

In FIG. 4 of this example, the controller 410 adjusting a reference voltage level V _ref V _o voltage received as input, and also controls grid current i _s to eliminate or reduce its harmonic and allowed to phase with the grid voltage While operating as a unit power factor or close (for example, PF = 99.99%). The exemplary implementation of the controller 410 is shown schematically in Figure 4, where the current and / or voltage from the sensor is sampled by the controller 410 as required (eg, approximately every 20 microseconds).

The voltage regulator V _o to attempt to minimize the error by adjusting the reference current (i _s ^*) amplitude. In this example, the shape of the current reference is generated from a unit sample of the grid voltage to ensure the PFC mode. Finally, the controller output 320 is modulated by standard 4-carrier PWM technology to send the required pulses.

Experimental results of the battery charger rectifier 100 will now be described. In a specific test case, actual tests have been performed on a 5-level converter based on silicon carbide (SiC). Six 1.2KV, 40A SiC MOSFET types SCT2080KE are used as active switches. The proposed voltage balancing method integrated into the switching technology and the cascade controller is implemented on the dSpace1103, so the switching pulses are sent to the 5-level switch. The system parameters tested are listed in Table 4.

In alternative embodiments, the AC input (grid) voltage may be approximately 240V RMS, and the DC load may be greater than 350V, as provided by boost mode rectification in the manner described herein.

As shown in Figure 5, a steady-state result of 1 kW has been obtained. As shown, the output DC terminal voltage 3 is adjusted to 200V (Ch1, the reference point is represented by 0V2, corresponds to point 1 on the vertical axis, and has 4 units, as shown at the bottom of the figure, each representing 50.0V , Total 200V), acceptable voltage fluctuation is less than 10%. In addition, due to the effective voltage balance of V _C , V _{in is} formed by 5 identical voltage levels of 0, ± 100, ± 200V, and has lower harmonic pollution than the voltage level of level 2 level. Further, by the input voltage and current waveforms observed v _s PFC rectifier battery charger operation (Ch3, wherein the reference point from 0V corresponding to the vertical axis shows spot 4 100 - shown in FIG bottom, each representing 100.0V) and i _s (Ch4, the reference point is represented by 0A2, corresponding to the point on the vertical axis 4- as shown at the bottom of the figure, each representing 10.0A) Finally, the load current i _l (Ch2, the reference point is shown as 0A2, corresponding to point 2 on the vertical axis, as shown at the bottom of the figure, each representing 10.0A), which is measured at approximately 5A, which indicates the realization of a 1kW working system.

Figure 6 shows some other parameters measured by the AEMC ^™ power analyzer. It is understandable that the battery charger rectifier 100 was tested with the highest possible power factor (close to consistency) at 1kW, which reduced the amount of significant reactive power and achieved good performance of the line current controller synchronized with the grid voltage . In addition, due to the low harmonic pollution of the multi-level quasi-voltage waveform generated by the 5-level rectifier, the current THD is also very low (the IEEE519 and IEC61000 standards require the line current THD to be less than 5%).

In this test, a 50% load change was intentionally made (from 38Ω to 75Ω) to check the dynamic performance of the controller. As shown in Figure 7, the load current is reduced to approximately half the initial amplitude. Therefore, due to the change in the energy delivered to the load, V _o (Ch1, the reference point is represented by 0V2, corresponding to point 1 on the vertical axis, and as shown in the figure, each cell represents 50.0V) varies but through the controller and Voltage balancing technology is very stable without accidental overshoot or undershoot. In addition, the input AC current is synchronized with the grid voltage, and its amplitude changes at the same time to achieve a steady state mode. It should be understood that current harmonics are also eliminated during the conversion. In other words, when it is observed that the DC load is reduced by 50% (the load current i _l (Ch2) is reduced to 50%-the reference point 0A2 on the vertical axis corresponding to point 2), the DC voltage is controlled at a desired level.

The actual results of the battery charger rectifier 100 have shown good dynamic performance of the controller and voltage balancing technology, which have been integrated into the modulation process. The auxiliary capacitor voltage is maintained at the desired level adjustment section of appropriate low voltage fluctuations. Such a fast and accurate method of voltage balancing results in the generation of a 5-level quasi-sinusoidal voltage waveform at the input of a rectifier with a low harmonic content. This multi-stage waveform allows the use of small size filters to eliminate line current harmonics. The battery charger rectifier 100 can be, therefore, very suitable as a potential candidate for the application of an industrial rectifier as a traction system of an electric vehicle or a battery charger.

The voltage balancing technology has been designed and integrated into the switching mode to adjust the auxiliary capacitor voltage, which results in 5 identical voltage levels at the input of the rectifier to form a smooth voltage waveform with 5 levels and low harmonic content. A standard cascaded PI controller has been implemented on the proposed rectifier, in part because there is a single DC terminal at the output without any separate capacitors. Practical tests show that the battery charger rectifier 100 has good dynamic performance, and implements voltage balancing technology and controller under steady state and load changing conditions. It may also be a potential product in the PFC rectifier market.

In order to provide a 7-level / 3 capacitor implementation, two power switches and an additional low-voltage capacitor are required. The modulation module will also be changed to have six carriers. The voltage balancing unit will be changed because there will be more switching states to charge and discharge capacitors and regulate their voltage.

The battery charger rectifier 100 may be provided in a battery charger together with other parallel battery charger rectifier circuits of a similar structure. As shown in FIG. 8A, each of the batteries works in parallel to provide DC power to a load. To this end, the battery charger may include a housing that includes a connector back plate with multiple sockets for receiving multiple modules, each module including a battery charger rectifier of the type described herein, which may also be used A common controller as shown in Figure 8A. The advantage of this modular method is that the backplane can be installed first, and the service of a professional electrician may be used, and the end user can add or replace the module 100 as needed. The modularization method shown is not limited to any particular number of modules 100; however, the applicant has found that for a design using the rectifier described above, a 5 kW rectifier module is effective, and six such The module provides a combined DC charging power of 30 kW. This amount of power is suitable for high-speed battery charging while being feasible within the available power budget of most traditional single-phase power inlets.

For a practical embodiment, a battery charger includes a battery charger rectifier 100, which may include a user-replaceable DC vehicle charging cable and a charging plug, for example, having a compatible format for assembling standardized plugs / sockets in an EV (i.e. , SAE J1772, ChaDeMo, or others).

FIG. 8A also shows how a power storage battery and a charging controller (also referred to as a battery management system or BMS) 810 are connected to the battery charging controller interface 820 and the controller 830 through a charging cable 815. The charging cable 815 may provide a data connection to the interface 820 and a high-voltage DC conductor connected to the backplane 840. The interface 820 may include an interface known in the field of DC EV chargers that receives data or indications of signals from the BMS regarding voltage and / or current charging parameter information. The interface 820 may be associated with a computer for the main controller 830. The computer 830 may provide the V _ref value to the backplane 840 of the one or more rectifier circuits 100. Whether it is part of the circuit 100 or using a sensor as part of the backplane 840, the computer 830 can receive the current transmitted to the battery 810. The data interface, AC input and DC output connections of the module 100 are shown in Figure 10 and will be described in detail below. The computer 830 may be any suitable processor with program memory for managing change control.

In some embodiments of the present invention, as shown in FIG. 8B, the AC current from the electric input panel enters the connector. For example, the AC current can be directly directed to the switches of the power storage battery and the charge control unit to provide The user has a 2-level AC electric vehicle battery charger with AC output, or guides a rectifier circuit to provide a 3-level DC EV charger with DC output. Therefore, users can choose a 2-level AC EV or 3-level DC EV charger.

FIG. 8C shows that in one embodiment, the backplane can receive a connector or a module connector directly or through a switch. When the switch is connected to the backplane, the charger will have an AC output connected to the power storage battery, providing users with a level 2 AC EV battery charger.

Fig. 8D shows the same embodiment as Fig. 8C, in which the switch is physically removed from the module connector by the user, thus disconnecting the AC current provided to the AC output, and being rectified by one or more battery chargers Replacement, such as by the module 100 at a later time, so upgrade to a level 3 DC EV charger. This provides users with a cheaper installation of a Level 2 AC electric vehicle battery charger that works with all types of vehicles, but does not charge the vehicle quickly and efficiently, and it can be easily upgraded to faster, More efficient 3-level DC electric vehicle.

In some embodiments, this is shown in Figure 11. The switch may be in the form of a blade 200 with an overcharge prevention module and is connected directly to the backplane or through a module connector, similar to a rectifier Of leaves 100. In this embodiment, the blade 200 used is removed in order to replace it with a rectifier blade 100.

Those skilled in the art can understand that any type of connector can be used as the backplane. The purpose of the module connector is only to facilitate and simplify the installation process for the user. Any type of connector can be used as the backplane. Further, in some embodiments, the switch and backplane may be the same element with the ability to disconnect the AC output and redirect current to the rectifier circuit.

In addition, those skilled in the art will understand that even though it has been shown in different ways, the controller 830 and / or the battery charger controller interface 820 or other components of the charger may be provided as additional modules or similar blades, such as The rectifier blade 100 may be added to the device later. Therefore, the original charger may only be a backplane with input and output, which can be upgraded to a DC charging station only by adding some modules or blades on the backplane.

In addition, those skilled in the art will understand that the AC and DC outputs may use separate or identical physical sockets or cables. In some embodiments, the socket can communicate with a vehicle's charge controller.

FIG. 9 is a block diagram showing a battery charger for a power storage battery. The power inlet is connected to a local distribution transformer of the power grid through a sensor and a main circuit breaker having a predetermined current threshold. The sensor provides the amount of current drawn by the power inlet. The battery charging controller interface communicates with the power storage battery and receives a charging voltage value and a desired charging current value. The rectifier circuit is connected to an electrical input for receiving single-phase AC input power, and its output DC voltage can be any down or up conversion use, for example, a DC buck-boost converter circuit. The buck converter has a control input terminal, which defines an output DC voltage and current. As shown in FIG. 10, the controller 410 can control the buck-boost converter to output the required DC voltage and current.

In a broad aspect, the present disclosure provides a power converter connected to an AC input that converts power from the AC input to DC, including at least one high voltage capacitor for boosting with a peak voltage higher than the AC input Voltage storage power, rectifier circuit. The rectifier includes an inductor connected in series with the AC input, a low voltage capacitor, and two diodes or optionally two high voltage switches connected between the first AC input terminal and the opposite end of the high voltage capacitor, two The intermediate low voltage power switch is connected between the opposite end of the high voltage capacitor and the opposite end of the low voltage capacitor, and the two terminals of the low voltage power switch are connected between the opposite end of the low voltage capacitor and the second AC terminal, where the DC load Can be connected to the opposite end of a high voltage capacitor. The power converter includes a controller having at least one sensor for sensing current and / or voltage in the rectifier circuit and connected to two intermediate low-voltage power switches and two terminal low-voltage power switches. Gate input.

In some embodiments, the controller is operable to cause the rectifier circuit to operate in boost mode, where 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 voltages The power switch is switched in a redundant switching state in response to the measurement of the voltage present at the low voltage capacitor to maintain the low voltage capacitor at a predetermined portion of the desired voltage of the high voltage capacitor, thereby keeping the high voltage capacitor at the required high voltage The rectifier circuit provides a DC load and absorbs power to form a five-stage active rectifier with low harmonics at the AC input.

In some embodiments, the power converter has a bidirectional rectifier / inverter circuit and two controllers instead of a rectifier circuit, rather than a controller capable of bidirectional operation as a rectifier and an inverter. The bidirectional rectifier / inverter circuit includes an inductor connected in series with the AC port, a low voltage capacitor, two high voltage power switches connected between the first AC terminal and the opposite end of the high voltage capacitor, and two intermediate low voltage power supplies. The switch is connected between the opposite end of the high-voltage capacitor and the opposite end of the low-voltage capacitor, and the two-terminal low-voltage power switch connected between the opposite end of the low-voltage capacitor and the second AC terminal; wherein the DC port can be connected To the opposite ends of the high voltage capacitor. The power converter includes a first controller for a rectifier mode having at least one sensor for sensing current and / or voltage in a bidirectional rectifier / inverter and connected to two high-voltage power switches. Gate input, two intermediate low-voltage power switches, and two-terminal low-voltage power switches for the rectifier circuit to work in boost mode, where the voltage of the high-voltage capacitor is higher than the peak voltage of the AC input and controls the two high-voltage The voltage power switch is turned 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 switch are switched in a redundant switching state in response to the measurement of the voltage present at the low-voltage capacitor so that The low-voltage capacitor is held at a predetermined portion of the desired voltage of the high-voltage capacitor, thereby keeping the high-voltage capacitor at the required high voltage. The rectifier circuit provides a DC load and absorbs power to form a five-stage active rectifier. Low harmonics. The power converter has a second controller for inverter mode, which is connected to two high-voltage power switches, two intermediate low-voltage power switches, and two terminal low-voltage power switches, and is configured to generate and apply Signal waveforms for two high-voltage power switches, two intermediate low-voltage power switches, and two-terminal low-voltage power switches, including a first control signal for connecting a low-voltage capacitor to a DC port and an AC port in series and charging To a predetermined value DC port proportional to the voltage, and the second control signal is used to disconnect the low voltage capacitor from the DC port and connect it in series with the AC port to discharge the low voltage capacitor.

In FIG. 9, the network interface 902 may be a conventional data interface associated with the computer 830, such as Ethernet, Wi-Fi, and the like. The recording module 904, the power budget controller 906, the available power predictor 908 and the charging power program module 910 can be implemented by software stored in the memory of the computer 830 and executed by the processor of the computer 830 to execute the following Mentioned operation.

The recording module stores at least one parameter in the memory, which is derived from the current measured by the sensor, minus any power drawn by the rectifier circuit over time in each sub-cycle of each day. This parameter may be the maximum possible increase of the non-charged load of the current time period and the current non-charged load. One or more appliances that are turned on can cause a load jump. AC motors, such as heat pumps and air-conditioning compressor motors, typically draw at least twice the steady-state current at startup. It can be understood that the probability that the drawn power increases may be within a desired probability, for example, within a 97% probability.

The power predictor calculator can be used to receive the current draw value and record the module parameters, and provide the maximum charging load value according to the predetermined power inlet maximum power load. A user interface (not shown) can be used to set the maximum load value of the power inlet. The power budget controller receives the maximum charging load value, the desired charging voltage value and the desired charging current value from the battery management interface, and provides a control input to the rectifier circuit.

In one embodiment, the maximum possible increase is determined based on long-term observation data. Until such data is available, the available power predictor can run more conservatively, and as the certainty about the prediction increases, the predictor calculator can be bolder.

In another embodiment, changes in power consumption are analyzed to determine the number and size of major home loads. Then sense the behavior of these loads. It is estimated that open loads can only be closed, so they do not increase the risk of total loads. The probability of a load turning on depends on the state of other loads, the time of day, and the time of year. For example, if the water heater is turned off, due to the possibility of using water, it is more likely to be turned on at any given time from 7AM to 8AM than from 11pm to 6am. In the summer, electric heating loads are less likely to turn on, while air conditioning is more likely, and the opposite is true in winter. Based on the behavior pattern and the estimation of the current workload, the available power predictor can predict the largest possible instant increase in power.

The power budget controller considers the risk of the largest possible increase in power to determine how much power is available. When the required power is too large, the power budget controller causes the rectifier circuit and / or the DC-DC buck converter to regulate the DC power to be delivered to EV.

In addition, the power budget controller can consider battery degradation when setting the charge rate. This may involve reference to a predetermined maximum charging current or power value. As described below, the charging aggressiveness level selected by the user may also be referred to.

When the available power prediction module predicts that there may be an increased risk of exceeding the power budget (entering a limited number), an optional disconnectable load switch can be used to prevent a large number of loads from drawing power, resulting in exceeding the power budget. This can delay or change the increased load to avoid exceeding the power budget of the power inlet. A disconnectable load switch may include a line voltage power switch connected to one or more electrical loads and a power panel (e.g., a water heater) to prevent the load from drawing current from the power panel. Such an additional load may exceed the risk power budget . Preferably, the load switch includes a sensor, such as a current sensor, to measure whether the load is currently drawing power. In this way, the power budget controller can sense whether the load in question is drawing power. The disconnectable load switch can be equipped with a sensor when it is turned on to sense when the disconnected load seeks to draw power, and in this case, the power budget controller can decide to reconnect this after reducing the DC charging power accordingly. load.

Some loads that absorb high currents include control electronics that absorb small loads in standby, such as less than about 100 watts. In this case, the bypass low-power current can be included in the disconnectable load while the disconnectable load switch is open. An example of a low-power current bypass connection is an isolation transformer configured to provide approximately ten to tens of watts of power to an electronic device that can be disconnected from the load. When the load is on, the disconnectable load switch module can sense the power consumption of the isolation transformer load side, and then send a signal to the power budget controller to decide whether to reduce the DC charging power to allow the disconnectable load to be reconnected to full AC. Power supply, or whether DC charging should continue to be performed at the same rate. When the DC charging load demand ends, it then allows reconnectable disconnectable loads.

The embodiment in FIG. 9 includes a charging power program module. When the user is not in a hurry to charge the EV, the charging power program module responds to user input to suppress the charging rate. Although EVs may allow fast charging, and the embodiments disclosed herein may allow charging at approximately 25 kVA, repeated fast charging may reduce battery life. In addition, the charging power program module can be used to select a time program for charging, that is, to delay and / or customize power consumption based on time-varying energy costs and / or power availability within the power distribution network. The charging connector may, for example, provide a user interface for selecting a charging aggressiveness level, that is, a variable charging level when the battery requests high-speed charging. Alternatively, a network interface may be provided to allow a remote user interface to be used to set the charging power program parameters.

In some embodiments, the AC current input from the electrical input panel can be redirected by the user through a connector, such as a switch to the AC output, and from there directly to the power storage battery and bypass the rectifier circuit's charge control. The charger is therefore provided to the user to choose between AC or DC charging mode. In an alternative embodiment, the battery charger does not have a rectifier circuit, but has a backplane, and the rectifier circuit can be added to the backplane at a later time, providing users with a 3 that can be upgraded to power the power storage battery. 2 stage EV battery charger with 1 stage DC EV charger.

Those skilled in the art will understand that the backplane disclosed herein may be a simple connector, a backplane with a control unit, such as a power budget controller, an available power predictor, a network interface embedded therein and a charging power program module Or a backplane with a modular connector to which the control unit can be added.

Fig. 10 schematically shows a single "blade" 100 of the modular system shown in Fig. 8A. In the embodiment shown, a printed circuit board is provided along one edge with high-voltage AC and DC connectors and connectors for data interfaces. The blade 100 contains a power switch for a power converter, and in this embodiment, six switches S1 to S6 for a 5-level active rectifier and one switch S7 for a buck-boost converter each provide DC Step-down or step-up to DC.

The capacitor 120 is provided on a small module having a socket for a plug connected to the blade 100. The quality of the high voltage capacitor 120 is important for the correct and safe operation of the rectifier. Therefore, timely replacement is desirable. The socket may include an identification circuit, which may be read by the controller 410 to determine various information. First, it can be used to determine if a new capacitor has been installed as required. Second, it can be used to determine if the installed capacitor has been previously used. This can be achieved in a number of ways. For example, the controller 410 may report the unique ID identification of each capacitor 120 used by it to an external database. When a new capacitor is inserted, such a database can be queried. Alternatively, the identification circuit in the capacitor plug module may store information about use in a non-volatile memory that can be read by the controller 410. In this way, when a new capacitor module is connected to the blade 100, the controller 410 can determine whether the capacitor 120 should be considered brand new, partially used, or expired. In the event that the capacitor 120 has expired, the controller 410 may refuse to provide power and issue a warning to prompt replacement of the capacitor 120.

It should be understood that the way the connection is provided to the blade module 100 may use a cable connector instead of the edge connection shown. It should also be understood that the socket of the capacitor module may be provided on the blade 100, as shown in FIG. 10, or it may be provided elsewhere, such as in a separate portion of the backplane (see FIG. 8A).

The socket may include a switch for sensing that the capacitor plug module is removed or exposed for removal, so that powering off of one or more blades 100 may be completed to allow the capacitor module 120 to be safely removed and replaced. In the embodiment of FIG. 10, the blade 100 has its own controller 410, and a common controller 410 may be provided on the back panel to control switches from multiple blades.

The sensor module in Figure 10 is shown connected to measure the voltage, DC output current, and DC output voltage at the low voltage capacitor. Other values can be measured if required. The measured value is provided to the controller 410.

FIG. 11 shows a schematic diagram of an alternative embodiment of the present invention, in which an AC charging blade 1100 having an overcharge prevention module 1102 is disclosed. The AC current enters the blade from the AC input and is output from the AC output after passing through the overcharge prevention module 1102. The overcharge prevention module also provides the possibility of communicating with the charging controller interface to set the current and voltage of the alternating current output according to the requirements of the EV by using the date port. .

Referring to FIG. 12, there is shown an embodiment of the present invention in which a portable DC charging unit 1200 is provided. The portable DC charging unit includes a housing 1202 having an AC input 1204 and a DC output 1208. The AC input 1204 and the DC output 1208 are connected to an AC power source 1204 through a cable 1206 and to an EV through a cable 1210, respectively. The portable DC charging unit 1200 has one or more 5-level rectifier circuits.

In one embodiment, the portable DC charging unit 1200 is provided with a plurality of similarly structured 5-stage parallel battery charger rectifier circuits. As shown in FIG. 13, each circuit works in parallel to provide DC power to a load. To this end, the battery charger may include a housing 1202 may include a connector back plate 1302, the connector back plate 1302 has a plurality of sockets 1304 for receiving a plurality of blade modules 1306, each blade module including the type described herein 5-level battery rectifier circuit.

The advantage of this modular approach is that the portable charger can be sold with only a 5-level rectifier circuit, and the end user can add or replace the module 1306 as needed. The illustrated modularization method is not limited to any particular number of modules 1302.

In some embodiments, the portable charger unit can operate in a bi-directional mode or a uni-directional mode. In bidirectional mode, the portable charger can be used as an inverter or rectifier. In unidirectional mode, the converter acts as a rectifier in other embodiments of the invention as previously described.

In unidirectional mode, the 5-level rectifier circuit can have two diodes instead of two high-voltage switches, as shown in Figure 2D.

One advantage of the portable charging unit 1200 is that, unlike an on-board charging unit, it has a near unit power factor and draws low harmonic AC current from the utility / power source. In addition, in some embodiments, the portable charger unit 1200 can provide the capabilities of any other off-board charging unit, such as higher KW transmission, more complex battery management systems, managing battery heating, and building / home / grid, energy management The ability of the system to communicate, the energy transfer rate is higher. In addition, the disclosed portable charging unit 1200 can also choose to remove weight from the EV by removing the on-board charging unit and providing the portable charging unit 1200 as an alternative to charging the vehicle.

14A and 14B, in some embodiments, an electric vehicle may have a receiver 1402 in its luggage for a connector 1212, which has a sensor (not shown) connected to an indicator for a driver (Out), showing the presence of a portable DC charging unit. This will prevent users from forgetting the portable charging unit after charging is over or when leaving the location. The sensor can be as simple as a mechanical switch, which is pushed when the receiver 1402 receives a connector or any other type of mechanical, electrical or electronic sensor known in the art.

In some embodiments, instead of the receiver 1402, the electric vehicle has a different receiver for receiving the housing or cable of the portable DC charging unit 1200, which provides the same indication function.

In one embodiment, instead of the receiver 1402, the portable charging unit 1200 may have a wireless presence indicator, such as a radio frequency identification (RFID) or Bluetooth sensor, to indicate the presence of the portable DC charger in or near the vehicle.

Those skilled in the art will understand that the circuits described in this application, such as a 5-level rectifier circuit, can be used in any AC to DC conversion system, such as a DC power source, other EV chargers, any other type of battery charger, or any Other implementations require AC to DC conversion.

Although the above description has been provided in reference to specific examples, this is for illustration purposes only and is not a limitation on the present invention.

Claims (32)

    A battery charger for supplying power to a power storage battery. The battery charger includes: an AC input for receiving single-phase power from a power inlet; and a battery charge controller interface for communicating with the power storage battery and receiving a charging voltage A power converter connected to the AC input and responsive to the charging voltage value to convert the power from the AC input into a variable voltage DC power at a DC output according to the charging voltage value of a DC load The power converter includes: at least one high-voltage capacitor for storing electric energy at a voltage boosted higher than a peak voltage of the AC input; a rectifier circuit including: an inductor connected in series with the AC input, low A voltage capacitor, one of the following: two diodes connected between the first AC input terminal and the opposite end of the high voltage capacitor; and two high voltage switches connected between the first AC input terminal and the high voltage Between the opposite ends of the voltage capacitor, two intermediate low voltage power switches are connected between the opposite ends of the high voltage capacitor and Between the opposite ends of the low-voltage capacitor, and a two-terminal low-voltage power switch connected between the opposite end of the low-voltage capacitor and a second AC terminal, wherein a DC load may be connected to the high-voltage The opposite end of the capacitor; and a controller having at least one sensor for sensing current and / or voltage in the rectifier circuit and connected to the two intermediate low-voltage power switches and the two Gate input for the low voltage power switch on each terminal.         The charger of claim 1, wherein the controller is operative to cause the rectifier circuit to operate in a boost mode, wherein a voltage of the high-voltage capacitor is higher than the AC input And the two intermediate low-voltage power switches and the two-terminal low-voltage power switch are switched in a redundant switching state in response to a measurement of the voltage present at the low-voltage capacitor in order to switch the low The voltage capacitor is maintained at a predetermined portion of the desired voltage of the high voltage capacitor, thereby keeping the high voltage capacitor at the required high voltage, and the rectifier circuit provides the DC load and absorbs power as a five-stage active rectifier Has low harmonics at the AC input.         The charger according to any one of claims 1 or 2, wherein the battery charge controller interface is further connected to the power storage battery and receives a desired charging current value, and the power converter further Responsive to the desired charging current value to convert electrical energy from the AC input to DC power at a DC output at a variable current that does not exceed the desired charging current value of a DC load.         The charger according to any one of claims 1 to 3, further comprising a step-down converter circuit for converting DC power from the opposite end of the high-voltage capacitor to the charging voltage. Set the lower DC output voltage.         The charger according to any one of claims 1 to 4, further comprising a boost converter circuit for converting a direct current power from the opposite end of the high voltage capacitor to the charging voltage. Set a higher DC output voltage.         The charger according to any one of claims 1 to 5, including the socket-type connector for removing and replacing the high-voltage capacitor from the active rectifier circuit.         The charger according to item 6 of the patent application scope, wherein the high-voltage capacitor is integrated in a plug-in module, the plug-in module includes at least one electronic identification component and is used to connect the electronic identification component to The interface of the controller, wherein the controller is configured to prevent operation when the electronic identification component does not exist or fails to provide effective identification for the plug-in module.         The charger according to any one of claims 1 to 7, wherein the two intermediate low-voltage power switches and the two-terminal low-voltage power switch are switched at a frequency higher than 10 kHz.         The charger according to any one of claims 1 to 8, wherein the single-phase AC input is about 240V RMS, and the voltage of the DC output power is greater than 350V.         The charger according to any one of claims 1 to 9, wherein the charger includes a housing and at least one module, and the housing includes a connector back plate having a plurality of module sockets, The at least one module is connected in the module socket, and each of the modules includes the rectifier circuit, and the modules work in parallel to provide DC power to the load.         The charger according to item 10 of the scope of patent application, wherein the high-voltage capacitor of each of the modules is about 4 millifarads.         The charger according to item 10 or 11 of the scope of patent application, wherein each of the modules is capable of providing a DC load power greater than about 2 kW.         The charger according to any one of claims 1 to 12 of the patent application scope, further comprising a DC vehicle charging cable and a charging plug.         The charger according to any one of claims 1 to 10, wherein the charger is capable of providing a DC load power greater than 9.5 kW.         The charger according to any one of claims 1 to 14, wherein the charger is a portable charger, and the portable charger includes an AC input cable, a DC output cable, and a plurality of modules. A housing of a connector backplane of the socket, and at least one module connected to the module socket, each of the modules including the rectifier circuit, and the modules work in parallel to provide DC power to the load .         The charger according to any one of claims 1 to 15, wherein the power converter includes a power inlet power sensor and a power draw increase prediction module, and the power inlet power sensor is used for measuring Power drawn from the power inlet of its distribution transformer, and the power draw increase prediction module has an input for receiving the value of the power drawn and an output that provides the largest possible jump in the power drawn at the power inlet The power converter is configured to limit the current level output by the power converter in order to prevent the power drawn at the power inlet from exceeding a predetermined limit when a maximum possible jump in the drawn power occurs.         The charger according to item 15 of the patent application scope, wherein the electric vehicle has a receiver having a presence sensor to indicate the presence of a connector of the portable charger.         The charger described in item 14 or 15 of the patent application scope includes one of the following: radio frequency identification (RFID); a Bluetooth sensor to indicate the presence of a portable charger in or near the vehicle.         The battery charger according to any one of claims 1 to 18, wherein the rectifier circuit is a bidirectional rectifier / inverter circuit, and the bidirectional rectifier / inverter circuit includes a serial connection with an AC port. An inductor, a low voltage capacitor, two high voltage power switches connected between a first AC terminal and an opposite end of the high voltage capacitor, the opposite end of the high voltage capacitor, and the low voltage capacitor Two intermediate low-voltage power switches between opposite ends of the two, and two-terminal low-voltage power switches connected between the opposite end of the low-voltage capacitor and a second AC terminal; wherein the DC port can be connected to The opposite end of the high-voltage capacitor; the controller is a first controller for a rectifier mode, the first controller having at least one sensor for sensing the bidirectional rectifier / inverter Current and / or voltage in the controller and connected to the gate inputs of the two high voltage power switches, the two intermediate low voltage power switches and the two terminals The low-voltage power switch is used to make the rectifier circuit work in a boost mode, wherein the voltage of the high-voltage capacitor is higher than the peak voltage of the AC input, and the two high-voltage power supplies are controlled in an ON relationship and an AC The input frequency is turned on and off, and the two intermediate low-voltage power switches and the two-terminal low-voltage power switch are switched in a redundant switching state in response to a measurement of a voltage present at the low-voltage capacitor, In order to keep the low voltage capacitor at a predetermined portion of the desired voltage of the high voltage capacitor, thereby keeping the high voltage capacitor at the required high voltage, the rectifier circuit provides a DC load and absorbs power as a five-stage active rectifier, Having low harmonics at the AC input; and the power converter further comprising a second controller for inverter mode, the second controller being connected to the two high-voltage power switches, the two An intermediate low-voltage power switch and the two-terminal low-voltage power switch, and configured to generate and apply to the two high-voltage power switches, The two intermediate low-voltage power switches and the two-terminal low-voltage power switch emit a signal waveform, the signal waveform includes a first control signal and a second control signal, and the first control signal is used to make the low-voltage capacitor Is connected in series with the DC port and the AC port and is charged to a predetermined value proportional to the voltage of the DC port, and the second control signal is used to disconnect the low-voltage capacitor from the DC port and from the DC port The AC ports are connected in series to discharge the low voltage capacitor.         The battery charger according to any one of claims 1 to 19 of the scope of patent application, which comprises an AC output for charging a level 1 or 2 EV and a circuit for disconnecting the power converter and switching between the AC input and the AC. An AC current switch is connected between the outputs.         A level 2 AC EV battery charger that can be upgraded to a level 3 DC EV charger for supplying power to a power storage battery. The battery charger includes:-a housing including: a unit for receiving single-phase power from a power inlet; AC input; AC output; DC output; connector backplane with at least one module connector, suitable for accommodating at least one DC power converter module for connecting AC input and DC output; and a switch for connecting AC input And AC output current.         The battery charger according to item 21 of the patent application scope, wherein the switch is controlled by the at least one DC power converter module.         The battery charger of claim 22, wherein the switch must be turned on to allow the at least one DC power converter module to be physically installed.         The battery charger according to item 23 of the patent application scope, wherein the switch is a socket-type connector.         The battery charger according to any one of claims 21 to 24, further comprising an overcharge prevention module that prevents the AC output voltage from exceeding a desired charging voltage and prevents the AC output current from exceeding a desired charging current.         The battery charger according to any one of claims 21 to 25, further comprising a battery charge controller interface for communicating with a power storage battery and receiving a charging voltage value and a desired charging current value.         A battery charger for supplying power to a power storage battery. The battery charger includes: an AC input for receiving single-phase power from a power inlet; and a power inlet power sensor for measuring power from the power inlet Power drawn by distribution transformers; power draw increase prediction module with an input for receiving the value of the drawn power and an output that provides the largest possible jump in power drawn at the power inlet; a battery charge controller interface For communicating with a power storage battery and receiving a charging voltage value; and a power converter connected to the AC input and responsive to the charging voltage value and the desired charging current value, so The AC input power is converted into a DC variable voltage at a DC output, and the power converter is configured to limit the current level output by the power converter so as to jump as much as possible in the drawn power When this occurs, the power drawn at the power inlet is prevented from exceeding a predetermined limit.         The battery charger according to item 27 of the scope of patent application, wherein the power converter includes a charging power program module having a user input interface for receiving user input defining charging aggressiveness parameters, wherein, the The charging power program module controls the current level over time in response to the charging aggressiveness parameter.         The charger according to claim 27 or 28, wherein the user input interface for receiving user input includes providing at least one switch on the charging plug.         The charger according to any one of claims 27 to 29, further comprising a network interface, wherein the user input interface for receiving user input includes a user of a remote device connected to the network interface interface.         The charger according to any one of claims 27 to 30, wherein the charging power program module records a history of a charging current so that an evaluation of battery degradation can be performed.         The charger according to any one of claims 27 to 31, further comprising a disconnectable load switch; wherein the power draw increase prediction module is connected to the disconnectable load switch for use when When the near-maximum possible jump value in the drawn power poses a danger of exceeding the predefined limit, temporarily disconnecting at least one of the disconnectable loads that can be connected to the disconnectable load switch, the power draw increases prediction module And configured to reconnect the disconnectable load when the power draw increase prediction module determines that an approach risk exceeding the predetermined limit has subsided.