DE102022203490A1 - Stationary induction charging device - Google Patents

Abstract

The invention relates to a stationary induction charging device (1) for an inductive vehicle charging system. The induction charging device (1) specifically comprises an active electrical power adjustment unit (2) for adjusting the electrical power to be absorbed by an external three-phase electrical alternating voltage source (50) and for rectifying the three phases (U, V,) provided by the voltage source (50). W) into a rectified electrical voltage (VGR). The induction charging device (1) further comprises a half-bridge inverter (20) electrically connected to the electrical power adjustment unit (2) for converting the rectified electrical voltage (VGR) generated by the electrical power adjustment unit (2) into an electrical output square-wave voltage (VA). The induction charging device (1) also comprises an electrical resonator (30) which is electrically connected to the half-bridge inverter (20) and has at least one induction coil (31). The resonator (30) is designed to generate an alternating magnetic field using the electrical output square-wave voltage (VA) generated by the half-bridge inverter (20).

Description

The invention relates to a stationary induction charging device for a vehicle charging system and a vehicle charging system with such a stationary induction charging device.

Conventional vehicle charging systems for electrically charging a battery of a motor vehicle typically include a stationary induction charging device, which can also be referred to as a floor assembly or ground assembly and which is usually arranged in a stationary manner, for example at a vehicle parking space, and connected to an electrical power network, and a mobile induction charging device , which can also be referred to as a vehicle assembly and which is arranged on the respective vehicle, in particular on the vehicle floor. The mobile induction charging device is coupled to the battery of the vehicle in a suitable manner, for example via a corresponding charger on the vehicle. To charge the battery, the vehicle with its mobile induction charging device is positioned with respect to the stationary induction charging device in such a way that electrical energy can be transferred from a resonator of the stationary induction charging device or from an induction coil of this resonator to the mobile induction charging device by means of induction, i.e. via an alternating electromagnetic field . With the inductive vehicle charging system, there is no need for wired electrical connections and, as a result, electrical plugs that have to be plugged into vehicle-side charging sockets.

Conventional stationary induction charging devices must be supplied with electrical energy from a 3-phase electrical alternating voltage source as soon as the electrical power they process exceeds a predetermined threshold value due to legal requirements. Likewise, legal requirements often require that a so-called active power factor correction - hereinafter also referred to as a "power adjustment unit" - be connected electrically upstream of the actual induction charging device in order to prevent unwanted or unauthorized feedback into the electrical alternating voltage source - in practice typically a public electrical power grid. to reduce.

It is therefore an object of the present invention to show new ways in the development of stationary induction charging devices. In particular, an improved embodiment of such a stationary induction charging device is to be created, in which the aforementioned problem is addressed.

The basic idea of the invention is therefore to combine a 3-phase power adjustment unit with an electrical half-bridge inverter as the central components of a stationary induction charging device. The 3-phase power adjustment unit is used to convert the three phases of the external AC voltage into a DC voltage. For this purpose, the power adjustment unit can be equipped with a pulse rectifier that has a step-up converter characteristic. This means that the rectified output voltage generated by the pulse rectifier is so large that the electrical transmission of this output voltage to the resonator of the induction charging device or to the induction coil of the resonator can take place using a half-bridge inverter, which is technically much simpler than a full-bridge inverter known from conventional induction charging devices . This creates an induction charging device for processing a three-phase alternating voltage that is very inexpensive to produce, yet powerful and - due to its simple technical structure - requires relatively little installation space.

The stationary induction charging device according to the invention proposed here specifically comprises an active electrical power adjustment unit for rectifying the three phases provided by a voltage source into a rectified, adjustable electrical voltage, preferably while reducing repercussions on the external voltage source. Furthermore, the induction charging device comprises a half-bridge inverter electrically connected to the electrical power adjustment unit for converting the rectified electrical voltage generated by the electrical power adjustment unit into an electrical output square-wave voltage. The induction charging device also includes an electrical resonator that is electrically connected to the half-bridge inverter and has at least one induction coil. The resonator is designed to generate an alternating magnetic field using the electrical output square-wave voltage generated by the half-bridge inverter.

In a preferred embodiment, the electrical power adjustment unit comprises a three-phase three-point pulse rectifier - hereinafter also referred to simply as a "pulse rectifier" - for rectifying the three phases provided by the three-phase electrical alternating voltage source into the rectified electrical voltage. The three-phase three-point pulse equal Richter has a relatively low harmonic component on its AC voltage side. In addition, compared to other types of rectifiers, it can generate particularly high electrical direct voltages, so that it can be operated in conjunction with a technically simple half-bridge inverter, which converts the voltage rectified by the pulse rectifier into an electrical alternating voltage - then into a square-wave voltage. In addition, the electrical power or voltage passed on from the power adjustment unit to the half-bridge inverter can be adjusted using pulse width modulation (PWM) using the pulse converter. The electrical power adjustment unit with the pulse rectifier is particularly preferably designed as a step-up converter.

According to an advantageous development, the three-phase three-point pulse rectifier has a first, second and third AC phase connection for connecting one of the three phases. The three phase inputs are electrically connected by means of an electrical rectifier circuit to two electrical rectifier outputs for providing an electrical voltage rectified by means of the rectifier circuit.

The electrical rectifier circuit preferably has a first, second and third electrical rectifier line path. The three rectifier line paths each extend from one of the three AC electrical phase inputs to a common electrical rectifier node. In this rectifier node, the three rectifier line paths are electrically connected to one another. In this development, an inductance and a controllable rectifier semiconductor switch are arranged in each of the three line paths.

In the context of the present invention, a “rectifier” semiconductor switch is to be understood as meaning a semiconductor switch which forms part of the rectifier circuit explained above and thus of the three-phase three-point pulse rectifier also explained above. Such a semiconductor switch can be a suitable power transistor, which can be switched in particular between a blocking state and a conduction state, the blocking state corresponding to an open switch and the conduction state corresponding to a closed switch. A MOSFET, which is characterized by a high operating frequency with almost no power control, is particularly suitable as a semiconductor switch.

The inductance and the rectifier semiconductor switch are preferably each arranged electrically in series with one another. In this development, each of the three rectifier line paths is connected to a first of the two electrical rectifier outputs by means of a first semiconductor diode. In addition, each of the three rectifier line paths is connected to a second of the two electrical rectifier outputs by means of a second semiconductor diode. Furthermore, the rectifier node is capacitively coupled to the first rectifier output via a first rectifier capacitance. Likewise, the rectifier node is coupled to the second rectifier output via a second rectifier capacitance.

In a preferred embodiment, the first and second rectifier capacitances are electrically connected to one another by means of an electrical rectifier connecting line. In this embodiment, the electrical node is connected, preferably with a low resistance, to the electrical rectifier connecting line.

In another preferred embodiment, the three first semiconductor diodes are each arranged in the forward direction between the respective electrical rectifier line path and the first rectifier output. In addition, in this embodiment, the three second semiconductor diodes are each arranged in the reverse direction between the respective electrical rectifier line path and the second rectifier output.

The half-bridge inverter particularly expediently comprises an electrical half-bridge circuit with two controllable semiconductor switches for generating the electrical output square-wave voltage.

In another preferred embodiment, the half-bridge inverter has first and second inverter inputs and first and second inverter outputs. In this embodiment, the first inverter input is electrically connected to a common inverter node via a first inverter semiconductor switch and the second inverter input is electrically connected to a common inverter node via a second inverter semiconductor switch. In the context of the present invention, an “inverter” semiconductor switch is to be understood as meaning a semiconductor switch which forms part of the half-bridge inverter explained above. Such a semiconductor switch can be a suitable power transistor, which can be switched in particular between a blocking state and a conduction state, the blocking state corresponding to an open switch and the conduction state corresponding to a closed switch. A MOSFET, which is characterized by a high operating frequency with almost no power control, is particularly suitable as a semiconductor switch.

Said inverter node is electrically connected to the first inverter output, preferably with a low resistance. Particularly preferred in this embodiment is that the second input is additionally electrically connected to the second inverter output, preferably with a low resistance. According to an advantageous development, the resonator has a first and second resonator input, which are connected to one another by means of an electrical resonator line path. The at least one induction coil is arranged in this resonator line path. In this development, the first resonator input is electrically connected to the first inverter output. Accordingly, the second resonator input is electrically connected to the second inverter output. Furthermore, at least one resonator capacitance and at least one resonator inductance are arranged in the resonator line path to form a passive impedance matching network. The at least one resonator capacitance and the at least one resonator inductance together with the at least one induction coil form an electrical resonant circuit.

According to a further advantageous development, a variable capacitance can be arranged in the resonator line path for active impedance matching, which can then also be part of said resonant circuit.

The invention further relates to a vehicle charging system with a stationary induction charging device according to the invention presented above, so that the advantages of the stationary induction charging device according to the invention explained above are transferred to the vehicle charging system according to the invention. The vehicle charging system according to the invention also comprises a mobile induction charging device which can be inductively coupled or coupled to the stationary induction charging device and which is designed for installation in a vehicle.

Further important features and advantages of the invention emerge from the subclaims, from the drawing and from the associated description of the figures based on the drawing.

It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or alone, without departing from the scope of the present invention.

Preferred exemplary embodiments of the invention are shown in the drawing and are explained in more detail in the following description, with the same reference numbers referring to the same or similar or functionally the same components.

The only 1 shows in a circuit diagram-like representation an example of a stationary induction charging device 1 according to the invention. The stationary induction charging device 1 comprises an active electrical power adjustment unit 2 for rectifying the three phases U, V, W provided by an external voltage source 50 into a rectified, adjustable electrical voltage V _GR , with reduction of repercussions on the external voltage source 50. For this purpose, the electrical power adjustment unit 2 comprises a three-phase, three-point pulse rectifier 3. The electrical power adjustment unit 2 with the pulse rectifier 3 is designed as a step-up converter.

The pulse rectifier 3 includes a first, second and third AC phase input 4a, 4b, 4c for connecting one of the three phases U, V, W. The three phase inputs 4a, 4b, 4c are electrically connected to two electrical rectifier outputs 6a, 6b by means of an electrical rectifier circuit 5. The rectifier circuit 5 serves to provide an electrical voltage V _GR that is rectified by means of the rectifier circuit 5.

According to 1 the rectifier circuit 5 of the pulse rectifier 3 has a first, second and third electrical rectifier line path 7a, 7b, 7c. The three rectifier line paths 7a, 7b, 7c each extend from one of the three electrical AC phase inputs 4a, 4b, 4c to a common electrical rectifier node 8, the so-called “three point”. In this rectifier node 8, the three rectifier line paths 7a, 7b, 7c are electrically connected to one another. In each of the three line paths 7a, 7b, 7c, an inductor 9a, 9b, 9c and a controllable rectifier semiconductor switch 10a, 10b, 10c are each arranged electrically in series with one another. Each of the three rectifier line paths 7a, 7b, 7c is connected to a first of the two electrical rectifier outputs 6a by means of a first semiconductor diode 11a.1, 11b.1, 11c.1. For this purpose, an electrical conduction path 14a can extend from the first rectifier output 6a to the three first semiconductor diodes 11a.1, 11b.1, 11c.1. Furthermore, each of the three rectifier line paths 7a, 7b, 7c is connected to a second of the two electrical rectifier outputs 6b by means of a second semiconductor diode 11a.2, 11b.2, 11c.2. For this purpose, an electrical line path 14b can extend from the second rectifier output 6b to the three second semiconductor diodes 11a.2, 11b.2, 11c.2. The rectifier node 8 is capacitive to the first rectifier via a first rectifier capacitance 12a ter output 6a coupled. The rectifier node 8 is also coupled to the second rectifier output 6b via a second rectifier capacitance 12b. The first rectifier capacitance 12a is electrically connected to the second rectifier capacitance 12b by means of a first electrical rectifier connecting line 13.

How 1 Also illustrated, the electrical node 8 is connected in a low-resistance, electrically conductive manner to the electrical rectifier connecting line 13. The three first semiconductor diodes 11a.1, 11b.1, 11c.1 are each arranged in the forward direction between the respective electrical rectifier line path 7a, 7b, 7c and the first rectifier output 6a in the line path 14a. In addition, the three second semiconductor diodes 11a.2, 11b.2, 11c.2 are each arranged in the reverse direction between the respective electrical rectifier line path 7a, 7b, 7c and the second rectifier output 6b in the electrical line path 14b.

According to 1 The induction charging device 1 further comprises a half-bridge inverter 20 which is electrically connected to the electrical power adjustment unit 2. The half-bridge inverter 20 serves to convert the electrical voltage V _GR rectified by the electrical power adjustment unit 2 into an electrical output square-wave voltage V _A. For this purpose, the half-bridge inverter 20 comprises an electrical half-bridge circuit 21 with two controllable semiconductor switches 22a, 22b for generating the electrical output square-wave voltage VA.

The half-bridge inverter 20 or the half-bridge circuit 21 has a first and second inverter input 23a, 23b and a first and second inverter output 24a, 24b. The first inverter input 23a is electrically connected to a common inverter node 26 by means of a first inverter semiconductor switch 22a and the second inverter input 23b by means of a second inverter semiconductor switch 22b. The inverter node 26 has a low resistance, i.e. it is connected directly to the first inverter output 24a. In addition, the second input 23b, also low-resistance, is electrically connected to the second inverter output 24b via an electrical line path 15. The half-bridge circuit 21 can be electrically grounded between the second inverter input 23b and the second inverter output 24b and, for this purpose, can be connected to an electrical ground potential 38 with low electrical resistance.

According to 1 Finally, the induction charging device 1 comprises an electrical resonator 30 which is electrically connected to the half-bridge inverter 20 and has at least one induction coil 31. The resonator 30 is designed to generate an alternating magnetic field by means of the electrical output square-wave voltage V _A generated by the half-bridge inverter 20.

The resonator 30 has a first and second resonator input 32a, 32b, which are electrically connected to one another by means of an electrical resonator line path 33. In addition, the first resonator input 32a is electrically connected to the first inverter output 24a in a low-resistance manner. Accordingly, the second resonator input 32b is electrically connected to the second inverter output 24b with a low resistance.

An induction coil 31 for generating an alternating magnetic field is arranged in the resonator line path 33. Using the alternating magnetic field, energy can be transmitted wirelessly to the... 1 mobile induction charging device, not shown. The first resonator input 32a is electrically connected to the first inverter output 24a. The second resonator input 32b is electrically connected to the second inverter output 24b. Furthermore, two resonator capacitances 34a, 34b and a resonator inductance 35 are arranged in the resonator line path 33 to form a passive impedance matching network. One of the two resonator capacitances is arranged electrically parallel to the induction coil 31 in the resonator line path 33, the other resonator capacitance 34b, like the resonator inductance 35, is electrically arranged in series with the induction coil 31 in the resonator line path 34. The three resonator capacitances 34a, 34b, 37 and the resonator inductance 35, together with the at least one induction coil 31, form an electrical oscillating circuit.

In the example scenario 1 A variable capacitance 37, which is also part of the resonant circuit, is also arranged in the resonator line path 33, electrically in line with the induction coil for active impedance matching.

The stationary induction charging device 1 explained above as an example can be part of a vehicle charging system according to the invention (not shown). This vehicle charging system also includes a mobile induction charging device that can be inductively coupled or coupled to the stationary induction charging device 1 and is designed for installation in a vehicle or is installed in such a vehicle.

Claims (12)

Stationary induction charging device (1) for a vehicle charging system, - with an active electrical power adjustment unit (2) for rectifying the three phases (U, V, W) provided by the voltage source (50) into a rectified, adjustable electrical voltage (V _GR ), preferably while reducing repercussions on the voltage source (50 ), - with a half-bridge inverter (20) electrically connected to the electrical power adjustment unit (2) for converting the rectified electrical voltage (V _GR ) generated by the electrical power adjustment unit (2) into an electrical output square-wave voltage (V _A ), - with a Electrical resonator (30) electrically connected to the half-bridge inverter (20) and having at least one induction coil (31) for generating an alternating magnetic field by means of the electrical output square-wave voltage (V _A ) generated by the half-bridge inverter (20). Induction charging device Claim 1 , characterized in that the electrical power adjustment unit (2) has a three-phase three-point pulse rectifier (3) for rectifying the three phases (U, V, W) provided by the three-phase electrical alternating voltage source (50) into the rectified electrical voltage (V _GR ). Induction charging device Claim 1 or 2 , characterized in that the electrical power adjustment unit (2), in particular the three-phase three-point (3), is designed as a step-up converter. Induction charging device Claim 2 or 3 , characterized in that the pulse rectifier (3) has a first, second and third AC phase input (4a, 4b, 4c) for connecting one of the three phases (U, V, W), which via an electrical rectifier circuit (5) are electrically connected to two electrical rectifier outputs (6a, 6b) for providing an electrical voltage (V _GR ) rectified by means of the rectifier circuit (5). Induction charging device according to one of the Claims 2 until 4 , characterized in that - the pulse rectifier (3), in particular the electrical rectifier circuit (5), has a first, second and third electrical rectifier line path (7a, 7b, 7c), each of which extends from one of the three electrical AC phase inputs (4a, 4b, 4c) to a common electrical rectifier node (8), in which the three rectifier line paths (7a, 7b, 7c) are electrically connected to one another, - in each of the three rectifier line paths (7a , 7b, 7c) an inductor (9a, 9b, 9c) and a controllable rectifier semiconductor switch (10a, 10b 10c), preferably electrically arranged in series with one another, - each of the three rectifier line paths (7a, 7b, 7c ) is each connected to a first of the two electrical rectifier outputs (6a) by means of a first semiconductor diode (11a.1, 11b.1, 11c.1) and each by means of a second semiconductor diode (11a.2, 11b.2, 11c. 2) is connected to a second of the two electrical rectifier outputs (6b), - the rectifier node (8) being capacitively coupled to the first rectifier output (6a) via a first rectifier capacitance (12a) and via a second Rectifier capacitance (12b) is coupled to the second rectifier output (6b). Induction charging device Claim 5 , characterized in that - the first and the second rectifier capacitance (12a, 12b) are electrically connected to one another by means of an electrical rectifier connecting line (13), - the electrical node (8), preferably low-resistance, to the electrical rectifier connecting line (13) is connected. Induction charging device Claim 5 or 6 , characterized in that - the three first semiconductor diodes (11a.1, 11b.1, 11c.1) are each arranged in the forward direction between the respective electrical rectifier line path (7a, 7b, 7c) and the first rectifier output (6a). are, - the three second semiconductor diodes (11a.2, 11b.2, 11c.2) are each arranged in the reverse direction between the respective electrical rectifier line path (7a, 7b, 7c) and the second rectifier output (6b). Induction charging device according to one of the preceding claims, characterized in that the half-bridge inverter (20) comprises an electrical half-bridge circuit (21) with two controllable semiconductor switches (22a, 22b) for generating the electrical output square-wave voltage (V _A ). Induction charging device according to one of the preceding claims, characterized in that - the half-bridge inverter (20), in particular the half-bridge circuit (21), a first and second inverter input (23a, 23b) and a first and second inverter output (24a, 24b ), - the first inverter input (23a) is electrically connected to a common inverter node (26) by means of a first inverter semiconductor switch (22a) and the second inverter input (23b) by means of a second inverter semiconductor switch (22b). is, which is electrically connected, preferably with low resistance, to the first inverter output (24a), - additionally the second inverter input (23b), preferably with low resistance, is electrically connected to the second inverter output (24b). Induction charging device according to one of the preceding claims, characterized in that - the resonator (30) has a first and second resonator input (32a, 32b), which are connected to one another by means of an electrical resonator line path (33), in which the at least one Induction coil (31) is arranged, - the first resonator input (32a) is electrically connected to the first inverter output (24a) and the second resonator input (32b) is electrically connected to the second inverter output (24b), - in Resonator line path (33) to form a passive impedance matching network at least one electrical resonator capacitance (34a, 34b) and at least one resonator inductance (35) are arranged, which together with the at least one induction coil (31) form an electrical resonant circuit. Induction charging device Claim 10 , characterized in that a variable capacitance (37) is arranged in the resonator line path (33) for active impedance matching. Inductive vehicle charging system, with a stationary induction charging device (1) according to one of the preceding claims and with a mobile induction charging device which can be inductively coupled or coupled to the stationary induction charging device (1), and which is designed for installation in a vehicle.

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