WO2021209643A1

WO2021209643A1 - Configurable voltage system for power consumer or power source

Info

Publication number: WO2021209643A1
Application number: PCT/EP2021/060055
Authority: WO
Inventors: Jan Johansson
Original assignee: Blixt Tech Ab
Priority date: 2020-04-17
Filing date: 2021-04-19
Publication date: 2021-10-21
Also published as: EP4136732A1

Abstract

The present invention relates to a configurable voltage system (100) for an external power consumer and/or an external power source. The configurable voltage system (100) comprises: a first port (P1) including a first side (S1_P1) configured to be connected to a first power consumer/source (210, 220); a first set of voltage modules (112) connected to a second side (S2_P1) of the first port (P1); a second set of voltage modules (122) connected to the second side (S2_P1) of the first port (P1); an overlap transfer circuit (300) connected between the first set of voltage modules (112), the second set of voltage modules (122) and the second side (S2_P1) of the first port (P1); wherein the overlap transfer circuit (300) is configured to: simultaneously transfer electrical power from the first set of voltage modules (112) and the second set of voltage modules (122) to the first power consumer (210) during an overlap time period; or simultaneously transfer electrical power from the first power source (220) to the first set of voltage modules (112) and the second set of voltage modules (122) during an overlap time period. Thereby, a power efficient and flexible voltage system is provided.

Description

CONFIGURABLE VOLTAGE SYSTEM FOR POWER CONSUMER OR POWER SOURCE

Technical Field

The invention relates to a configurable voltage system for an external power consumer and/or an external power source.

Background

Different types of voltage or power systems are known in the art. A voltage system may be configured to feed an electrical load or drive an electrical motor by electrical power. The latter e.g. being part of an electrical vehicle or a hybrid vehicle.

The voltage system may also be configured to receive power, i.e. to be loaded by an external power source, such as a wind power plant or a solar power plant.

Therefore, examples of voltage systems are systems for driving an electrical motor of electrical vehicles or hybrid vehicles. Other non-limiting examples are power systems coupled to wind power plants and solar power plants.

Summary

An objective of embodiments of the invention is to provide a solution which mitigates or solves the drawbacks and problems of conventional solutions.

The above and further objectives are solved by the subject matter of the independent claims. Further advantageous embodiments of the invention can be found in the dependent claims.

According to a first aspect of the invention, the above mentioned and other objectives are achieved with a configurable voltage system comprising: a first port including a first side configured to be connected to a first power consumer/source; a first set of voltage modules connected to a second side of the first port; a second set of voltage modules connected to the second side of the first port; an overlap transfer circuit connected between the first set of voltage modules, the second set of voltage modules and the second side of the first port; wherein the overlap transfer circuit is configured to: simultaneously transfer electrical power from the first set of voltage modules and the second set of voltage modules to the first power consumer during an overlap time period; or simultaneously transfer electrical power from the first power source to the first set of voltage modules and the second set of voltage modules during an overlap time period.

The voltage system may also be denoted as an electrical power system. The voltage consumer may e.g. be an electrical load or an electrical motor. The power source is a power source that feeds a system with electrical power such as battery packs, wind power plants, solar power plants, grid power system or any other suitable power source.

An advantage of the configurable voltage system according to the first aspect is that switching and deadtime losses are reduced or eliminated compared to conventional solutions since no deadtimes are used. Further, a continuous current can be provided to the load which means that components used for compensating for deadtimes as in conventional solutions, such as inductors and capacitors, are not needed.

Also since the set of voltage modules are modular service on the set of voltage modules can be simplified. Further, the safety aspect is much improved since the voltage levels to be handled during service is only that of each module instead of a dangerously high voltage level of multiple connected batteries as in conventional solutions.

In an embodiment of a configurable voltage system according to the first aspect, the overlap transfer circuit comprises a first controllable switch configured to be coupled between the first set of voltage modules and the first power consumer/source; a second controllable switch configured to be coupled between the second set of voltage modules and the first power consumer/source.

In an embodiment of a configurable voltage system according to the first aspect, the first controllable switch is configured to receive first control signals and the second controllable switch is configured to receive second control signals, so that both the first controllable switch and the second controllable switch both are conductive during the overlap time period, wherein the first control signals and the second control signals are simultaneous or non-simultaneous clocked.

In an embodiment of a configurable voltage system according to the first aspect, the first control signals and the second control signals are non-simultaneous clocked with a time offset dependent on at least one of: a current provided to the power consumer, currents provide by the power source to the first and second sets of voltage modules, and a difference in output voltage between the first and second sets of voltage modules.

In an embodiment of a configurable voltage system according to the first aspect, each voltage module is configured to operate in: a serial mode in which its voltage is added to a common/output voltage of its set of voltage modules, or a parallel mode in which its voltage is shared to one or more other voltage modules in its set of voltage modules.

Thereby, different voltage values and waveforms may be provided.

In an embodiment of a configurable voltage system according to the first aspect, the common/output voltage of a set of voltage modules is dependent on the number of voltage modules in serial mode in the set of voltage modules.

In an embodiment of a configurable voltage system according to the first aspect, each set of voltage modules comprises at least one voltage module configured to have a nominal voltage and at least one voltage module configured to have a variable voltage.

Thereby, more flexibility when forming different voltage values and waveforms.

In an embodiment of a configurable voltage system according to the first aspect, wherein each voltage module further is configured to operate in: a measure mode in which its voltage is measured.

In an embodiment of a configurable voltage system according to the first aspect, the configurable voltage system is configured to determine control parameters based on measured voltages of the voltage modules; and control an output voltage of the first set of voltage modules and/or the second set of voltage modules based on the control parameters.

Thereby, higher performance and lower losses is possible in the system.

In an embodiment of a configurable voltage system according to the first aspect, the configurable voltage system is configured to adapt the output voltage of the first set of voltage modules and/or the second set of voltage modules to a nominal voltage of the first power consumer/source based on the control parameters.

An advantage with this embodiment is that the voltage system can be adapted to the external power consumer or the external power source in terms of their nominal power. Therefore, the power of the configurable voltage system can be used very efficiently with low losses.

A nominal voltage can be understood as an expected voltage, an operating voltage of the load, a working voltage, etc. Different types of nominal voltages may be considered. One type is static or more or less constant, meaning a constant nominal voltage value, e.g. for an external power consumer or the external power source demanding a constant power. Another type is when the nominal voltage value takes discrete values which e.g. may be predefined, e.g. different power levels of a microwave oven. Yet another type is when the nominal voltage value can take continuous values, e.g. an electrical motor of a vehicle such as a car or a truck.

In an embodiment of a configurable voltage system according to the first aspect, the configurable voltage system comprises at least one equalizing switch coupled between a positive line of the first set of voltage modules and a positive line of the second set of voltage modules, and wherein a difference in output voltage between the first set of voltage modules and the second set of voltage modules is equalized when the equalizing switch is set in conductive mode.

The equalizing switches of the system may be controlled based on mentioned control parameters and/or threshold values.

Thereby, voltages and currents can be shared between the sets of voltage modules in the system.

In an embodiment of a configurable voltage system according to the first aspect, the configurable voltage system comprises a second port including a first side configured to be connected to a second power consumer/source; a third set of voltage modules connected to a second side of the second port; and a fourth set of voltage modules connected to the second side of the second port.

Thereby, the system can be extended. In an embodiment of a configurable voltage system according to the first aspect, the configurable voltage system comprises an additional overlap transfer circuit connected between the third set of voltage modules the fourth set of voltage modules and the second side of the second port.

In an embodiment of a configurable voltage system according to the first aspect, the first power consumer/source and the second power consumer/source are the same power consumer/source.

In an embodiment of a configurable voltage system according to the first aspect, the configurable voltage system comprises equalizing switches coupled between the positive lines of the first, second, third and fourth sets of voltage modules.

In an embodiment of a configurable voltage system according to the first aspect, each voltage module in the system comprises a voltage depot including a first connection coupled to a first common line and a second connection coupled to a second common line, and a switching arrangement coupled to the voltage depot; and a control arrangement configured to control each voltage module to operate in: a first mode in which a voltage of its voltage depot is added to a common voltage of a set of voltage modules, or a second mode in which a voltage of its voltage depot is shared to one or more other voltage modules in the set of voltage modules.

The first mode of a voltage module can also be denoted as an active mode and the second mode can be denoted as a non-active mode. Hence, each set of voltage modules of the system may be considered as active when at least one of its voltage modules is in active mode, i.e. the first mode, so that an output voltage, also denoted as a common voltage, of the active set of voltage modules is larger than zero; and as non-active when all of its voltage modules are in non-active mode, i.e. the second mode, so that an output voltage of the non-active set of voltage modules is zero.

In an embodiment of a configurable voltage system according to the first aspect, each voltage depot includes a battery. An advantage with this embodiment is that it is especially suitable for direct current (DC) applications.

In an embodiment of a configurable voltage system according to the first aspect, each voltage depot includes a capacitor.

An advantage with this embodiment is that a capacitor can be loaded faster in comparison to a battery.

In an embodiment of a configurable voltage system according to the first aspect, each voltage depot includes a battery and a capacitor, and the battery and the capacitor are coupled in parallel to each other between the first common line and the second common line.

In an embodiment of a configurable voltage system according to the first aspect, each voltage depot may include a transformer. The transformer may have 1 :1 relation between its primary and secondary windings.

Therefore, each voltage depot may include any combinations of batteries, capacitors and transformers.

In an embodiment of a configurable voltage system according to the first aspect, a control arrangement is configured to control a voltage module by controlling its switching arrangement, the control arrangement being configured to control each switching arrangement to operate in: a first switching mode in which the voltage depot is coupled in series with one or more other voltage depots of the first set of voltage modules so that its voltage is added to the common voltage of the first set of voltage modules, or a second switching mode in which the voltage depot is coupled in parallel with one or more other voltage depots of the first set of voltage modules so that its voltage is shared with to one or more other voltage modules in the first set of voltage modules.

In an embodiment of a configurable voltage system according to the first aspect, each switching arrangement includes a first switch coupled between the first connection of the voltage depot and a first connection of an adjacent voltage depot, a second switch coupled between the second connection of the voltage depot and a second connection of the adjacent the voltage depot, and a third switch coupled between the first connection of the voltage depot and the second connection of the adjacent the voltage depot.

In an embodiment of a configurable voltage system according to the first aspect, the switching arrangement in the first switching mode, the first switch and the second switch are switched OFF when the third switch is switched ON; and in the second switching mode, the first switch and the second switch are switched ON when the third switch is switched OFF.

Further applications and advantages of the embodiments of the invention will be apparent from the following detailed description.

Brief Description of the Drawings

The appended drawings are intended to clarify and explain different embodiments of the invention, in which:

- Fig. 1 shows a configurable voltage system according to an embodiment of the invention;

- Fig. 2 illustrates a set of voltage modules of a configurable voltage system according to an embodiment of the invention;

- Fig. 3 illustrates a voltage module having a switching arrangement according to an embodiment of the invention;

- Fig. 4 illustrates two different voltage modules each having a three switch switching arrangement according to an embodiment of the invention;

- Fig. 5 shows a first set of voltage modules according to an embodiment of the invention;

- Fig. 6 shows a first set of voltage modules coupled to a second set of voltage modules according to an embodiment of the invention;

- Fig. 7 and 8 show overlap circuits according to embodiments of the invention;

- Figs. 9 - 11 illustrate an overlap circuit according to embodiments of the invention;

- Fig. 12 shows an embodiment of the invention including a control device;

- Figs. 13 - 15 illustrate different aspects of controlling the controllable switches;

- Fig. 16 shows a plurality of sets of voltage modules coupled to each other according to an embodiment of the invention;

- Fig. 17 shows a plurality of sets of voltage modules coupled to a common power source/consumer according to an embodiment of the invention; and

- Fig. 18 illustrates a configurable voltage system comprising two ports which may be coupled to a power consumer or a power source. Detailed Description

Fig. 1 shows a configurable voltage system 100 according to an embodiment of the invention. The configurable voltage system 100 comprises a first set of voltage modules 112a, 112b,..., 112n and a control arrangement 102 configured to control each voltage module 112n. The control arrangement 102 can e.g. control each voltage module 112n via switches or any other suitable components. The control arrangement 102 can control the voltage modules via control signalling illustrated with the dashed arrows from the control arrangement 102 to the voltage modules 112a, 112b,..., 112n. Suitable control protocols may be used in this respect and be performed over known wired communication means, such as CAN busses or other communication busses. Also, wireless communication means can be used by the control arrangement 102 for controlling the components of the system 100. The control arrangement 102 may e.g. comprise one or more processors and one or more memory units and may be connected to one or more sensors and devices from which the control arrangement may receive input that may be used for controlling the voltage modules and other components of the configurable voltage system 100. More details of such aspects are described in the following disclosure.

The control arrangement 102 may operate using a switching or a clock frequency when controlling the different components of the configurable voltage system 100. For example, the switching frequency of the control arrangement may be higher than or equal to 10 kFIz and lower than or equal to 300 kFIz. If the frequency is lower than 10 kFIz it will be difficult to provide good alternating current (AC) waveforms such as a sinusoid curve. On the other hand, if the frequency is higher than 300 kFIz the efficiency of the system will be reduced due to switching losses in the system. The control arrangement 102 may use the same or different clock frequencies for different components of the system and for different applications. For example, the clock frequency for the overlap circuit may be higher than the clock frequency for the voltage modules or vice versa.

The configurable voltage system 100 further comprises a first port P1 including a first side S1 pi configured to be connected to an external power consumer 210 or an external power source 220 and a second side S2_Pi configured to be connected to the first set of voltage modules 112a, 112b,..., 112n. The first port P1 thus allows voltage and hence power to be supplied to and from the configurable voltage system 100. For example, voltage may be supplied from one or more of the first set of voltage modules 112a, 112b,..., 112n to the external power consumer 210 or voltage may be supplied from the external power source 220 to one or more of the first set of voltage modules 112a, 112b,..., 112n. With reference to Fig. 2, each voltage module 112n in the first set of voltage modules 112a, 112b,..., 112n comprises an voltage depot 114n including a first connection 116n coupled to a first common line L1 of the first set of voltage modules 112a, 112b,..., 112n and a second connection 118n coupled to a second common line L2 of the first set of voltage modules 112a, 112b,..., 112n. 11. The second common line L2 may be coupled to the second side S2P_I of the first port P1 , as shown in Fig. 2.

According to embodiments of the invention, each voltage depot 114n includes at least one of a battery B and a capacitor C, see Fig. 3. In embodiments when the voltage depot 114n includes both a battery B and a capacitor C, the battery B and the capacitor C may be coupled in parallel to each other between the first common line L1 and the second common line L2. The batteries herein may be any suitable batteries known in the art and with any voltage rating. Non-limiting examples are Lithium battery rated is 3.6V and 3 - 4 Ah. With 6 such batteries in series, the rated voltage of a voltage module would become 21 .6 V. The voltage range per module goes from discharged to fully charged 18V-25V. Other non-limiting examples are LiFe, Lilon and LiFe batteries. SuperCap batteries can also be interesting. The capacitors herein may be any suitable capacitors known in the art. For example, in C modules, ceramic capacitors are selected for the modules' maximum voltage. These have relatively low Ri, which means low heating and heat loss during loading and unloading. A suitable minimum capacitor value is with a BLOCK-time of 2.5ps (200kFlz) and a voltage drop <1% and 10A current to the load = 100pF. This is conveniently achieved by connecting a number of ceramic capacitors in parallel. Capacitors with different value, voltage resistance and chemistry may be included in a parallel circuit to minimize resistance.

In embodiments of the invention, each voltage depot may include a transformer T, see Fig. 3. The transformer may have 1 :1 relation between its primary and secondary windings. Therefore, each voltage depot may include any combinations of batteries B, capacitors C and transformers T. The transformers herein may be any suitable transformer known in the art. For example, with < 10A current and 25V rated voltage per module, the power requirement may be at least 250VA. A non-limiting example is CoilCrafts PL300-100 with 1 :1 coupling which is designed for 300W at 200kFlz. The 1 :1 ratio, implying unregulated voltage transmission, means that rings, etc. undesirably can be reduced to a minimum.

In embodiments of the invention, each voltage depot has a nominal (fixed) voltage or a variable or tuneable voltage. In a non-limiting example, each voltage depot can have 25 V so that for each activate voltage module the set of voltage module will have a common/output voltage that is equal to the number of activated modules times 25 V. However, for fine tuning the output voltage each set of voltage modules may have one or more voltage modules that can provide voltages with higher granularity, e.g. from 1.2 V up to 21.6 V in steps of 1.2 V, i.e. 18 units. The voltage depots can e.g. be built with one or more batteries coupled in the voltage depot. It is noted that the actual voltage of a battery depends on if the battery is charged or discharged.

Therefore, in embodiments, each set of voltage modules comprises at least one voltage depot having a nominal voltage and at least one voltage depot having a variable voltage. Thereby, the common/output voltage of each set of voltage modules can be adjusted, e.g. to the nominal voltage of the external power consumer or the external power source. Furthermore, by activating and de-activating voltage modules, e.g. with a rate set by a clock frequency used by the control arrangement 102, different waveforms can be generated. Therefore, e.g. sinusoidal AC waveforms can be generated at the output of the configurable system 100.

In a low complex implementation example, each set of voltage modules has at least one voltage depot having a nominal voltage and a single voltage depot having a variable voltage. By having only one voltage depot having a variable voltage also the cost can be held low but still provide adaptability of the value of the common voltage for each set of voltage modules.

Each voltage module 112n further comprises an internal switching arrangement 120n coupled to the voltage depot 114n. The control arrangement 102 is configured to control each voltage module 112n to operate in a first mode M1 , also denoted serial or active mode, in which an voltage of its voltage depot 114n is added to a common voltage of the first set of voltage modules 112a, 112b,..., 112n, or a second mode M2, also denoted parallel or non-active mode, in which an voltage of its voltage depot 114n is shared to one or more other voltage modules in the first set of voltage modules 112a, 112b,..., 112n. The control arrangement 102 may control each voltage module 112n between the first mode M1 and the second mode M2 by controlling the switching arrangement 120n of the voltage module 112n. Thus, the control arrangement 102 may in embodiments be configured to control a voltage module 112n by controlling its switching arrangement 120n. The control arrangement 102 may be configured to control each switching arrangement 120n to operate in a first switching mode SM1 in which the voltage depot 114n is coupled in series with one or more other voltage depots of the first set of voltage modules 112a, 112b,..., 112n so that its voltage is added to the common voltage of the first set of voltage modules 112a, 112b,..., 112n; or a second switching mode SM2 in which the voltage depot 114n is coupled in parallel with one or more other voltage depots of the first set of voltage modules 112a, 112b,..., 112n so that its voltage is shared with to one or more other voltage modules in the first set of voltage modules 112a, 112b,..., 112n. Fig. 3 illustrates such embodiments of the invention. The switching arrangement of the voltage module can switch the voltage module between the first mode M1 (also denoted active mode) and the second mode M2 (also denoted non-active mode), respectively. In Fig. 3 the switching arrangement is in the first switching mode SM1 and therefore the voltage depot 114 will be serially coupled to a voltage depot of an adjacent voltage module (not shown) which means the voltage of this particular voltage module will be added to the common/output voltage of the set of voltage modules it belongs to. Therefore, the common voltage of a set of voltage modules will be the sum of all its voltage modules that are in its first mode M1 . Flowever if the switching arrangement is in its second switching mode SW2 the voltage depot will be coupled in parallel with an voltage depot of an adjacent voltage module which means that the voltage of the voltage depot will be equalized with other voltage depots in the set of voltage modules that are in the second mode M2. Therefore, the voltage will be equalized among the voltage modules that are in the second mode M2. If all voltage modules of a set of voltage modules are coupled in parallel with each other the common or output voltage of the set will be zero.

In embodiments of the invention, each switching arrangement 120n includes three switches. Fig. 4 shows such switching arrangement 120a of a first voltage module 112a according to an embodiment of the invention. The switching arrangement 120a includes a first switch SW1 , a second switch SW2, and a third switch SW3 and is coupled between the first voltage module 112a and an adjacent second voltage module 112b. Therefore, the switching arrangement includes a first switch SW1 coupled between the first connection 116n of the voltage depot 114n and a first connection 116n of an adjacent voltage depot 114n, a second switch SW2 coupled between the second connection 118n of the voltage depot 114n and a second connection 118n of the adjacent the voltage depot 114n, and a third switch SW3 coupled between the first connection 116n of the voltage depot 114n and the second connection 118n of the adjacent the voltage depot 114n. Fig. 4 only shows first 112a and second 112b voltage modules for illustration but it is realised that a set of voltage modules can comprise any number of voltage modules.

The control arrangement 102 may be configured to control each switching arrangement 120n to operate in the first SM1 and second SM2 switching modes by controlling the first switch SW1 , the second switch SW2, and the third switch SW3, respectively. For example, in the first switching mode SM1 , the first switch SW1 and the second switch SW2 are switched OFF when the third switch SW3 is switched ON; and in the second switching mode SM2, the first switch SW1 and the second switch SW2 are switched ON when the third switch SW3 is switched OFF. A switch that is switched ON can be understood to fed/led current/voltage, i.e. allow current to pass through the switch, while a switch that is switched OFF can be understood to not fed/led any current/voltage, i.e. prevent current to pass through the switch.

With further reference to Fig. 4, the first switch SW1 is coupled between the first connection 116a of the first voltage depot 114a and the first connection 116b of the second voltage depot 114b, the second switch SW2 is coupled between the second connection 118a of the first voltage depot 114a and the second connection 118b of the second the voltage depot 114b, and the third switch SW3 is coupled between the first connection 116n of the first voltage depot 114a and the second connection 118b of the second voltage depot 114b. It is further noted that the first switch SW1 and the second switch SW2 are not switched at the same time instance as the third switch SW3, or vice versa, since this would result in a short circuit.

The control arrangement 102 may control the first switching arrangement 120a to operate in the first SM1 and second SM2 switching modes. As previously described, in the first switching mode SM1 , the first switch SW1 and the second switch SW2 are switched OFF when the third switch SW3 is switched ON. This means that the first voltage depot 114a is coupled in series with the second voltage depot 114b and hence that voltage can be added to the common voltage of the first set of voltage modules 112a, 112b,..., 112n. In the second switching mode SM2, the first switch SW1 and the second switch SW2 are switched ON when the third switch SW3 is switched OFF. Thus, the first voltage depot 114a is coupled in parallel with the second voltage depot 116b and hence that its voltage can be shared to one or more other voltage modules in the first set of voltage modules 112a, 112b,..., 112n. The common voltage of a set of voltage modules may be denoted as a common voltage or an output voltage of the set of voltage modules when the voltage depots are voltage depots, such as batteries, capacitors, and transformers.

The control arrangement 102 may further be configured to control each voltage module 112n to operate in a third mode M3 in which a voltage of the voltage depot 114n is measured. In this case, each voltage module 112n may comprise a measuring resistance R coupled in parallel to the second switch SW2 and between the second connection 118n of the voltage depot 114n and a second connection 118n of an adjacent voltage depot 114n. This is illustrated in Fig. 5.

The measuring resistance R may have the same value for all voltage modules and may be used for voltage sharing between different voltage modules. The measuring resistance R can e.g. be of SMD type which allows the transistors in each voltage module to be of LV type. If measuring resistance R is selected too large, the voltage distribution may be dependent on the leakage currents of the voltage module's other components. If measuring resistance R on the other hand is selected too little, the power consumption may be unnecessarily high. For example, the value may be higher than 1 kQ/V so that each 25V voltage module could have a value higher than 25kQ. This means a "leakage" of max 1 mA, which means loss of max 0.25W at 250V.

By having the first SW1 , the second SW2 and the third switches SW3 in their OFF mode, the voltage can be measured over the second switch SW2. Such measurements can be used by the control arrangement 102 or a processing device (not shown) for determining relevant control parameters such as if the current is DC or AC, frequency of AC, amplitude of the voltage/current, etc. Based on such control parameters the control arrangement 102 can decide when and what to couple to the external power consumer or power source. If the system 100 should be coupled to an external power consumer the output voltage of the system 100 at the port should be higher than the nominal voltage of the external power consumer so that the external power consumer will be fed with power by the system 100. On the other hand, if the system 100 should be coupled to an external power source the output voltage of the system at the port should be lower than the nominal voltage of the external power source so that the system 100 is fed by the external power source. In other words, the control arrangement and hence the configurable voltage system 100 can be configured to:

• Obtain a nominal voltage of a power consumer or a power source.

• Obtain measurements from voltage modules of the system.

• Determine control parameters, such as DC, AC, waveform characteristics such as AC frequency, amplitude, phase, based on the one or more measurements.

• Control and/or adapt an output voltage or a common voltage of the sets of the voltage modules of the system 100 to the nominal voltage of the power consumer or the power source based on the control parameters.

More generally, the configurable voltage system may be configured to determine control parameters based on measured voltages of voltage modules; and further to control an output voltage of the first set of voltage modules 112 and/or the second set of voltage modules 122 based on the control parameters. In a specific example, to adapt the output voltage of the first set of voltage modules 112 and/or the second set of voltage modules 122 to a nominal voltage of the first power consumer/source 210, 220 based on the control parameters.

In embodiments of the invention, the configurable voltage system 100 may comprise a controllable switch 130n of an overlap circuit. In the non-limiting disclosed example in Fig. 5, the controllable switch 130n is coupled between the first set of voltage modules 112a, 112b, ... , 112n and the second side S2_Pi of the first port P1. Also, the controllable switch 130n may be configured to be controlled by the control arrangement 102. When the controllable switch 130n is in ON mode the set of voltage modules are conductively coupled to the first port P1 . More about this aspect of the invention will be described in the following disclosure with reference to the previously mentioned overlap circuit. It is further noted that voltage module 112a and 112c are in the second mode M2 while voltage module 112c is in the first mode in the example in Fig. 5. Thereby, the common voltage or the output voltage will be the voltage of voltage module 112b in this particular non-limiting example.

With reference to Fig. 6, in embodiments of the invention, the configurable voltage system further comprises at least one second set of voltage modules 122a, 122b,..., 122n connected to the second side S2_Pi of the first port P1. Each voltage module 122n in the second set of voltage modules 122a, 122b,..., 122n comprises an voltage depot 124n including a first connection 126n coupled to a first common line L1 ^' of the second set of voltage modules 122a, 122b,..., 122n and a second connection 128n coupled to a second common line L2^' of the second set of voltage modules 122a, 122b,..., 122n and a switching arrangement 126n coupled to the voltage depot 124n.

As shown in Fig. 6 the first common line L1 ^' of the second set of voltage modules 122a, 122b,..., 122n may be coupled to the first common line L1 of the first set of voltage modules 112a, 112b,..., 112n via an equalizing switch 410^'; and the second common line L2^' of the second set of voltage modules 122a, 122b,..., 122n is coupled to the second common line L2 of the first set of voltage modules 112a, 112b,..., 112n via an equalizing switch 410. The control arrangement 102 is configured to control each voltage module 122n in the second set of voltage modules 122a, 122b,..., 122n to operate in the first mode M1 or in the second mode M2. As previously mentioned for the first set of voltage modules, the second set of voltage modules can comprise at least one voltage module with a nominal voltage value and at least one voltage module with variable voltage value so that the output voltage of the second set of voltage modules can be varied and adapted. It is further noted that each set of voltage modules has its associated high voltage switch 130a, 130b.

As further disclosed in Fig. 6 the configurable voltage system 100 further comprises an overlap transfer circuit 300 connected between and to the first set of voltage modules 112, the second set of voltage modules 122 and the second side S2_Pi of the first port P1 . The overlap transfer circuit 300 is configured to: simultaneously transfer electrical power from the first set of voltage modules 112 and the second set of voltage modules 122 to the first power consumer 210 during an overlap time period; or simultaneously transfer electrical power from the first power source 220 to the first set of voltage modules 112 and the second set of voltage modules 122 during an overlap time period depending on the application.

With reference to Fig. 7 and 8, according to embodiments of the invention, the overlap transfer circuit 300 comprises a first controllable switch 130a configured to be coupled between the first set of voltage modules 112 and the first power consumer/source 210, 220; and a second controllable switch 130b configured to be coupled between the second set of voltage modules 122 and the first power consumer/source 210, 220. Fig. 7 shows the case when the current is feed from the first 112 and second 122 sets of voltage modules to a power consumer 210 while Fig. 8 shows the case when a power source 220 feeds currents to the first 112 and second 122 sets of voltage modules.

With reference to Fig. 7 and Figs. 9-11 in embodiments of the invention: i) during a first time period T1 , the first controllable switch 130a is configured to feed a first current i_t from the first set of voltage modules 112 to the power consumer/load 210 when the second controllable switch 130b is configured to block a second current i₂ from the second set of voltage modules 122 to the power consumer 210; ii) during a second time period T2 following the first time period T1 , the first controllable switch 130a is configured to feed a first current i_t from the first set of voltage modules 112 to the power consumer 210 when the second controllable switch 130b is configured to feed a second current i₂ from the second set of voltage modules 122 to the power consumer 210; and iii) during a third time period T3 following the second time period T2, the first controllable switch 130a is configured to block a first current from the first set of voltage modules 112 to the power consumer 210 when the second controllable switch 130b is configured to feed a second current i₂ from the second set of voltage modules 122 to the power consumer 210. The second time period T2 therefore defines a time period when both the first and second power sources delivers current to the power consumer 210 at the same time. This time period may therefore be denoted an overlap power transfer time period or overlap time period. It is known that in conventional solutions the power transfer is not overlapping but instead separated using so called deadtimes. More about this will be explained in the following disclosure.

Further, in embodiments of the invention, iv) during a fourth time period T4 following the third time period T3, the first controllable switch 130a is configured to feed a first current i_t from the first set of voltage modules 112 to the power consumer 210 when the second controllable switch 130b is configured to feed a second current i₂ from the second set of voltage modules 122 to the power consumer 210. This case is not shown in the Figs but it is understood that the fourth time period T4 is also an overlap time period when both the first and second sets of voltage modules feed/supply current to the power consumer 210 at the same time. Moreover, steps i) to iv) described previously may be repeated any number of times.

It is also herein disclosed different methods for switching between the steps i) to iv). Generally, different conditions may be set or used for switching from state i) to ii). The conditions may relate to the output voltage of the first set of voltage modules and its associated threshold parameters and/or the output voltage of the second voltage modules and its associated threshold parameters. Therefore, in embodiments of the invention, the overlap circuit is configured to switch from i) to ii) when an output voltage of the first set of voltage modules 112 is smaller than a first threshold voltage V™; and/or switch from i) to ii) when an output voltage of the second set of voltage modules 122 is larger than a second threshold voltage V_Th2. The first threshold voltage V™ may be dependent a nominal voltage V_n of the power consumer 210, and/or the second threshold voltage V_Th2 is dependent on at least one of the first threshold voltage V™ and the nominal voltage V_n of the power consumer 210. A nominal voltage of the power consumer 210 can be understood as an expected voltage of the power consumer 210, an operating voltage of the power consumer 210, a working voltage of the power consumer 210, etc. Different types of nominal voltages may be considered. One type is static or more or less constant, meaning a constant nominal voltage value, e.g. for a power consumer 210 demanding a constant power. Another type is when the nominal voltage value takes discrete values which e.g. may be predefined, e.g. different power levels of a microwave oven. Yet another type is when the nominal voltage value can take continuous values, e.g. an electrical motor of a vehicle such as a car or a truck.

As aforementioned, the first threshold voltage V™ may be lower than the nominal voltage V_n of the power consumer 210 which means that the power consumer 210 has drained the power of the first set of voltage modules 112 to some extent. However, for proper functioning of the power consumer 210 the output voltage may not drop to much and therefore in further embodiments of the invention the first threshold voltage V™ is larger than 90 % of the nominal voltage V_n of the power consumer 210. It is however noted that the percentage of the nominal voltage is dependent on the application or type of the load and hence in embodiments of the invention, the first threshold voltage V™ is larger than X % of the nominal voltage V_n of the load, where X % is dependent on or based on the proper functioning of the load. In other words, the lower limit for the load to work or operate properly.

Another type of conditions primarily relates to the output voltage of the second set of voltage modules 122 but it will be envisaged that such conditions may also in turn depend on the conditions related to the output voltage of the first power source previously described. The second threshold voltage V_Th2 may be higher or equal to a nominal voltage V_n of the load. It has further been realised that the second threshold voltage V_Th2 may be dependent on at least one of the first threshold voltage V™ and the nominal voltage V_n of the power consumer 210. For example, the second threshold voltage V_Th2 may be higher than the first threshold voltage V_Thi and the nominal voltage V_n.

In embodiments of the invention, it is further determined a difference voltage between the first threshold voltage V™ and the nominal voltage V_n of the power consumer 210, and then the second threshold voltage V_Th2 is determined based on such a difference voltage. For example, the second threshold voltage V_Th2 may be set as the nominal voltage plus the difference voltage. A non-limiting example would be: nominal voltage V_n = 200 V, first threshold voltage V_Thi = 190 V, which means that 200 - 190 = 10 V is the difference voltage and hence the second threshold voltage V_Th2 is set to 10 + 200 = 210 V. The skilled person understands that when the system returns back from state iii) to state i) the aforementioned conditions can be applied, mutatis mutandis.

With reference to Fig. 8, according to embodiments of the invention: i) during a first time period T1 , the first controllable switch 130a is configured to feed a first current i_t from the power source 220 to the first set of voltage modules 112 when the second controllable switch 130b is configured to block a second current i₂ from the power source 220 to the second set of voltage modules 122; ii) during a second time period T2 following the first time period T1 , the first controllable switch 130a is configured to feed a first current from the power source 220 to the first set of voltage modules 112 when the second controllable switch 130b is configured to feed a second current i₂ from the power source 220 to the second set of voltage modules 122; and iii) during a third time period T3 following the second time period T2, the first controllable switch 130a is configured to block a first current

from the power source 220 to the first set of voltage modules 112 when the second controllable switch 130b is configured to feed a second current i₂ from the power source 220 to the second set of voltage modules 122. The second time period T2 is hence an overlap time period.

It may be noted that the general principles previously disclosed and explained with reference to Fig. 7, mutatis mutandis, also applies to the embodiment shown in Fig. 8. Therefore, in embodiments of the invention, iv) during a fourth time period T4 following the third time period T3, the first controllable switch 130a is configured to feed a first current i_t from the power source 220 to the first set of voltage modules 112 when the second controllable switch 130b is configured to feed a second current i₂ from the power source 220 to the second set of voltage modules 122. Moreover, steps i) to iv) described previously may be repeated any number of times.

It is also herein disclosed different methods for switching between the different steps i) to iv). Generally, different conditions may be set or used for switching from state i) to ii). The conditions may relate to a voltage of the first set of voltage modules 112 and its associated threshold parameters and/or the voltage of the second set of voltage modules 122 and its associated threshold parameters. Therefore, in embodiments of the invention the overlap circuit 300 is configured to switch from step i) to ii) when a voltage over the first set of voltage modules 112 is higher than a first threshold voltage V™ ; and/or switch from i) to ii) when a voltage over the second set of voltage modules 122 is smaller than a second threshold voltage V_Th2. The first threshold voltage V™ may be dependent a nominal voltage V_n of the first set of voltage modules 112, and/or the second threshold voltage V_Th2 is dependent on a nominal voltage V_n of the second set of voltage modules 122.

In embodiments of the invention, the first controllable switch 130a is configured to receive first control signals CTRL1 and the second controllable switch 130b is configured to receive second control signals CTRL2, so that both the first controllable switch 130a and the second controllable switch 130b both are conductive during an overlap time period, wherein the first control signals CTRL1 and the second control signals CTRL2 are simultaneous or non- simultaneous clocked. The control signals may be provided by the previously describe control arrangement 102. In case the first control signals CTRL1 and the second control signals CTRL2 are non-simultaneous clocked, a time offset between the first and second control signals may depend on at least one of: a current provided to a power consumer, currents provide by a power source to the first and second sets of voltage modules, and a difference in output voltage between the first and second sets of voltage modules. In yet further embodiments of the invention, the offset may also be dependent on the mentioned control parameters obtained by using the measurement modes of the voltage modules.

More specifically, the first control signals CTRL1 and the second control signals CTRL2 may comprise ON signals and OFF signals, e.g. ones and zeros (1/0). An ON signal sets a controllable switch, such as the first controllable switch 130a and second controllable switch 130b, in a conductive mode and an OFF signal sets a controllable switch in a non-conductive mode. Flence, in the conductive mode a current can pass through the controllable switch while in the non-conductive more the current is blocked and cannot pass through the controllable resistor device. With this reasoning the first control signals CTRL1 and the second control signals CTRL2 may be simultaneous or non-simultaneous clocked in relation to each other which may mean that the first and second control signals are sent or received at the same time instance or in different time instances. Both simultaneous or non-simultaneous clocked control signalling works well. In the latter case when the first control signals CTRL1 and the second control signals CTRL2 are non-simultaneous clocked there is a time offset between CTRL1 and CTRL2. The frequency, clocking and time offset may be determined based on the mentioned control parameters.

Fig. 13 shows control signalling according to prior art while Fig. 14 shows examples of control signalling according to embodiments of the invention. In Fig. 13 and 14, the x-axis shows time and the y-axis OFF state and ON state of respective controllable switches. It may be noted that when a control signal is received by a controllable switch there is always a delay from non conductivity to fully conductivity mode or state, or vice versa, which may be denoted raise time and fall time before the component is in fully conductive mode (ON) or in blocking mode (OFF). Further, a switch may also be represented as variable resistance having a varying resistivity with mentioned raise and fall times.

In Fig. 13, it is shown exemplary deadtimes DTs, i.e. DT1 - DT4, according to prior art. During such deadtimes no current is provided to a load since both resistors are in non-conductive or blocking mode, i.e. OFF. Between the deadtimes, each switch passes or feeds a current to the common load but never at the same time. Flence, during time period ON1 only a first switch is in ON state is passing current to the load. After deadtime DT2 during time period ON2 only a second switch is in ON state is passing current to the load as shown in Fig. 13.

Fig. 14 on the other hand shows when the first and second controllable switches are controlled according to embodiments of the invention with overlapping power transfer conductivity. It is firstly noted that no deadtimes exists at all in Fig. 14. This may be formulated such that there is no time period when both the first and second controllable switches are in non-conductive mode, i.e. in OFF state. Further, overlap or overlapping time periods are shown in Fig. 14, and during such an overlap power transfer time period both the first (ON state) and second (ON state) controllable switches are conductive and hence pass current to the load at the same time period. For example, during a first time period T 1 the first controllable switch is conductive when the second controllable switch is non-conductive, and during the second time period T2 both the first and second controllable switches are conductive. It is however to be noted that during the second time period T2, the resistance R1 of the first controllable switch is raising from fully conductive to fully non-conductive state while the resistance R2 of the second controllable switch is decreasing from fully non-conductive to fully conductive state. This also means that the current via the first controllable switch will decrease accordingly and the current via the second controllable switch will increase accordingly during the second time period T2. During the third time period T3 the second controllable switch is conductive when the first controllable switch is blocking.

It may further be noted that there is a certain time instance when the first and second controllable switches will have the same resistance values marked Tl in Fig. 14, and Fig. 15 shows more in detail such time instances disclosing two different examples TI1 and TI2. The vertical lines in Fig. 15 illustrates control signal CTRL1 , CTRL2 instances or clocking instances. In a first example the control signals for the first and second controllable switches are simultaneously clocked, denoted “Sim.” in Fig. 15, compared to a second example in which the control signals are non-simultaneously clocked, denoted “non-sim.” in Fig. 15.

In the first example in Fig. 15 during a first time period T1 only the first controllable switch is conductive. During second timer period T2 when Sim. 1 is clocked R1 starts to increase and at the same time R2 starts to decrease and both first and second controllable switches are hence conductive during T2. At time instance TI1 , the resistivity of R1 equals R2, R1 =R2. During the third time period T3 only the second controllable switch is conductive and the first controllable switch is therefore blocking. Flence, this is an example when there is no time offset in the clocking of control signals CTRL1 and CTRL2.

In the second example in Fig. 15, the situation during the first timer period T1 is the same as in the first example. Flowever, during time period T2^' a clocking time offset is introduced between CTRL1 and CTRL2 signals which may mean that time period T2^' is extended in time compared to time period T2. During time period T2^' the value of RT is increasing while the value of R2 is decreasing. The clocking offset means that a time instance TI2 when the resistivity of RT equals R2, R1 ^'=R2, is offset in time leading to a lower resistivity and hence higher current compared to the first example. Thereby, the current delivered to the load can be controlled by controlling the time offset. It has therefore been realised that the time offset may be dependent on at least one of:

• A current provided to the load 210, a voltage difference between the first and second sets of voltage modules, a resistance value when a resistance R1 of the first controllable switch 130a equals a resistance R2 of the second controllable switch 130b when considering the embodiment in Fig. 7; and

• Currents provided to the first and second sets of voltage modules, a voltage difference between the first and second sets of voltage modules, and a resistance value when a resistance R1 of the first controllable switch 130a equals a resistance R2 of the second controllable switch 130b when considering the embodiment in Fig. 8. With reference to Fig. 16 and 17, the configurable voltage system 100 may comprise a plurality of sets of voltage modules coupled to each other according to the above described principals. For simplicity, only the first L1 and the second L2 common line of the first set of voltage modules are shown but it is noted the first common line of each set of voltage modules are coupled to each other and correspondingly the second common line of each set of voltage modules are coupled to each other via equalizing switches of the type shown in Fig. 6. Therefore, the configurable voltage system 100 in embodiments of the invention comprises at least one equalizing switch 410 coupled between a positive line L1 of the first set of voltage modules 112 and a positive line LT of the second set of voltage modules 122. Thereby, a difference in output voltage between the first set of voltage modules 112 and the second set of voltage modules 122 is equalized and hence also the currents when the equalizing switch 410 is set in conductive mode. This equalizing principle can be extended to further sets of voltage modules as shown in Fig. 16 and 17 in which equalizing switches 410 are coupled between the positive lines of the different sets of voltage modules. The equalizing switches 410 can be controlled by the control arrangement and how they are controlled may be determined on the mentioned control parameters.

Furthermore, the configurable voltage system 100 may also comprises at least one second port P2 as shown in Fig. 16, 17 and 18. The second port P2 includes a first side S1 p₂configured to be connected to an external voltage consumer 210 or to an external voltage depot 220 and a second side S2_P2 coupled to at least one of the second common line L2 of the first set of voltage modules 112a, 112b,..., 112n and the second common line L2^' of the second set of voltage modules 122a, 122b,..., 122n. Hence, the present system may be coupled to a multiple ports P1 , P2,..., Pn which in turn are coupled to one or more power consumers and/or power sources. A power consumer may e.g. be an electrical load or an electrical motor. A power source may be configured to load the system with electrical power/energy, e.g. a wind power plant, a solar power plant, grid power system or any other suitable plant or power system. It is further noted from Fig. 17 that a common power source/consumer may be coupled between ports P1 and P2. 12. In other words, the first power consumer/source 210, 220 and the second power consumer/source 210^', 220^' may be the same power consumer/source so to speak. Therefore, the voltage system 100 may comprise additional overlap transfer circuits and Fig. 16 and 17 illustrates such cases. In Fig. 16 an overlap transfer circuit is coupled to a first port P1 and an additional overlap transfer circuit 300^' is connected between the third set of voltage modules, the fourth set of voltage modules and the second side S2_P2 of the second port P2. In Fig. 17 both overlap circuits 300 and 300^'are coupled to the common power consumer/source 210/220. Also, the overlap circuits of the system may be controlled based on the mentioned control parameters derived from measurements of the voltage modules.

The switches of the different switching arrangements herein may be any suitable switches known in the art. For example, solid state transistors, such as MOSFET or any other transistor types. The selected switch may depend on the application e.g. being high voltage or low voltage switches. For example, the switches in each module may be of a first type, the equalizing switches may be of a second type, and the controllable switches in an overlap transfer circuit may be of a third type, but they may also be of the same type. The high voltage switches may be any suitable high voltage switches known in the art. They should be able to handle much higher voltages than the switches in the voltage modules. For example, they could be able to handle voltages from 25 V up to 600 V if each voltage module provides 25 V.

Finally, it should be understood that the invention is not limited to the embodiments described above, but also relates to and incorporates all embodiments within the scope of the appended independent claims.

Claims

1 . A configurable voltage system (100), the configurable voltage system (100) comprising: a first port (P1 ) including a first side (S1 pi) configured to be connected to a first power consumer/source (210, 220); a first set of voltage modules (112) connected to a second side (S2_Pi) of the first port

(P1 ); a second set of voltage modules (122) connected to the second side (S2_Pi) of the first port (P1 ); an overlap transfer circuit (300) connected between the first set of voltage modules (112), the second set of voltage modules (122) and the second side (S2_Pi) of the first port (P1); wherein the overlap transfer circuit (300) is configured to: simultaneously transfer electrical power from the first set of voltage modules (112) and the second set of voltage modules (122) to the first power consumer (210) during an overlap time period; or simultaneously transfer electrical power from the first power source (220) to the first set of voltage modules (112) and the second set of voltage modules (122) during an overlap time period.

2. The configurable voltage system (100) according to claim 1 , wherein the overlap transfer circuit (300) comprises a first controllable switch (130a) configured to be coupled between the first set of voltage modules (112) and the first power consumer/source (210, 220); a second controllable switch (130b) configured to be coupled between the second set of voltage modules (122) and the first power consumer/source (210, 220).

3. The configurable voltage system (100) according to claim 2, wherein the first controllable switch (130a) is configured to receive first control signals (CTRL1 ) and the second controllable switch (130b) is configured to receive second control signals (CTRL2), so that both the first controllable switch (130a) and the second controllable switch (130b) both are conductive during the overlap time period, wherein the first control signals (CTRL1 ) and the second control signals (CTRL2) are simultaneous or non-simultaneous clocked.

4. The configurable voltage system (100) according to claim 3, wherein the first control signals (CTRL1 ) and the second control signals (CTRL2) are non-simultaneous clocked with a time offset dependent on at least one of: a current provided to the power consumer (210), currents provide by the power source (220) to the first (112) and second (122) sets of voltage modules, and a difference in output voltage between the first (112) and second (122) sets of voltage modules.

5. The configurable voltage system (100) according to any one of the preceding claims, wherein each voltage module is configured to operate in: a serial mode (M1) in which its voltage is added to a common/output voltage of its set of voltage modules, or a parallel mode (M2) in which its voltage is shared to one or more other voltage modules in its set of voltage modules.

6. The configurable voltage system (100) according to claim 5, wherein the common/output voltage of a set of voltage modules is dependent on the number of voltage modules in serial mode (M1) in the set of voltage modules.

7. The configurable voltage system (100) according to claim 5 or 6, wherein each set of voltage modules comprises at least one voltage module configured to have a nominal voltage and at least one voltage module configured to have a variable voltage.

8. The configurable voltage system (100) according to any one of claims 5 to 7, wherein each voltage module further is configured to operate in: a measure mode (M3) in which its voltage is measured.

9. The configurable voltage system (100) according to claim 8, configured to determine control parameters based on measured voltages of the voltage modules; and control an output voltage of the first set of voltage modules (112) and/or the second set of voltage modules (122) based on the control parameters.

10. The configurable voltage system (100) according to claim 9, configured to adapt the output voltage of the first set of voltage modules (112) and/or the second set of voltage modules (122) to a nominal voltage of the first power consumer/source (210, 220) based on the control parameters.

11. The configurable voltage system (100) according to any one of the preceding claims, comprising at least one equalizing switch (410) coupled between a positive line (L1) of the first set of voltage modules (112) and a positive line (LT) of the second set of voltage modules (122), and wherein a difference in output voltage between the first set of voltage modules (112) and the second set of voltage modules (122) is equalized when the equalizing switch (410) is set in conductive mode.

12. The configurable voltage system (100) according to any one of the preceding claims, comprising a second port (P2) including a first side (S1 p₂) configured to be connected to a second power consumer/source (210^', 220^'); a third set of voltage modules (132) connected to a second side (S2_P2) of the second port (P2); and a fourth set of voltage modules (142) connected to the second side (S2_P2) of the second port (P2).

13. The configurable voltage system (100) according to claim 12, comprising an additional overlap transfer circuit (300^') connected between the third set of voltage modules (132), the fourth set of voltage modules (142) and the second side (S2_P2) of the second port (P2).

14. The configurable voltage system (100) according to claim 10 or 11 , wherein the first power consumer/source (210, 220) and the second power consumer/source (210^', 220^') are the same power consumer/source.

15. The configurable voltage system (100) according to any one of claims 10 to 12, comprising equalizing switches (410) coupled between the positive lines of the first (112), second (122), third (132) and fourth (142) sets of voltage modules.