Charging and discharging control of energy devices in a power system
A control switch incorporating a 1:2 demultiplexer is used to control timing for a concurrent switching, break-before-make and make-before-break power multiplexing, and is configurable to link a plurality of the control switches into a control chain to perform sequential charging, sequential discharging, parallel charging, parallel discharging, and concurrent sequential charging and discharging for a plurality of batteries coupled to the control chain in a power system.
1. An apparatus for energy switching control, wherein the apparatus comprises a control section and a transfer section, wherein the transfer section comprises:
a power input port to receive energy;
a power output port; and
a transfer device adapted to transfer energy from the power input port to charge an energy device coupled to the power output port when the transfer device is enabled;
and the control section comprises:
a control input port to receive an enable input signal;
a control output port to output an enable output signal;
a status output port to monitor status of the transfer device;
an inhibit input port to receive an inhibit signal to negate the transfer device and to assert the enable output signal to a successive apparatus when the enable input signal is asserted;
a circuit adapted to compare an input voltage coupled to the energy device with a reference voltage to generate a detection output in response;
a charging control signal adapted to control charging operation of the energy device; and
a demultiplexer comprising:
a demultiplexer input coupled to the enable input signal;
a select control signal generated by Boolean operation of the charging control signal and the detection output to enable one of two demultiplexer outputs:
a positivity output signal generated by ANDing the demultiplexer input with the select control signal; and
a negativity output signal generated by ANDing the demultiplexer input with an inverse of the select control signal; wherein
one of the positivity output signal or the negativity output signal is coupled to the transfer device; and
the other one of the positivity output signal or the negativity output signal is coupled to the enable output signal to enable a succeeding apparatus.
2. The apparatus of claim 1 , wherein the status output port is coupled to a transfer enable signal input to the transfer device; and
the inhibit input port and the status output port form a control pair to control operation of the apparatus.
3. The apparatus of claim 1 , wherein both the positivity output signal and the negativity output signal are negated when the enable input signal is de-asserted; and wherein the demultiplexer controls switching between the apparatus and the succeeding apparatus when the enable input signal is asserted.
4. The apparatus of claim 1 , wherein the comparator output is saturated to a logic high value when the comparator input voltage is above the reference voltage, and the comparator output is saturated to a logic low value when the comparator input voltage is lower than the reference voltage.
5. The apparatus of claim 1 , wherein when inputs to the comparator are interchanged, the comparator output changes state thus causing state change of the select control signal input to the demultiplexer.
6. The apparatus of claim 1 , wherein the reference voltage is selected from a group consisting of an external input voltage, and an internal voltage.
7. The apparatus of claim 1 , wherein adjusting delay timing of the positivity output signal and the negativity output signal in the apparatus to achieve one of power multiplexing:
the transfer device in the apparatus and the transfer device in the succeeding apparatus change state concurrently;
the transfer device in the apparatus is switched off before the transfer device in the succeeding apparatus is switched on, prompting a break-before-make power multiplexing operation; and
the transfer device in the succeeding apparatus is switched on before the transfer device in the apparatus is switched off, prompting a make-before-break power multiplexing operation.
8. The apparatus of claim 1 , wherein the positivity output timing is adjusted by including a delay element along a timing path of the positivity output signal, wherein the delay element is selected from a group consisting of
a direct wiring interconnect,
a buffer,
an even number of inverters,
a delay-line, and
a programmable delay-line.
9. The apparatus of claim 1 , wherein the negativity output timing is adjusted by including an inverting delay element along a timing path to the negativity output signal, wherein the inverting delay element is selected from a group consisting of
an open drain inverter,
an inverting buffer,
an odd number of inverters,
an inverting delay-line, and
an inverting programmable delay-line.
10. The apparatus of claim 1 , wherein the apparatus is
a charging control switch when the power input port is configured to receive energy from a DC power source, and the comparator is configured to monitor energy on the energy device coupled to the power output port.
11. The apparatus of claim 1 , wherein the select control signal of the demultiplexer is derived by selecting one of:
coupling the charging control signal with the comparator output;
coupling the charging control signal with an inverted comparator output;
coupling the comparator output with the inhibit signal;
coupling the comparator output with one or more signals representative of one or more qualifying condition; and
coupling an inverted comparator output with one or more signals representative of one or more qualifying conditions.
12. The apparatus of claim 1 , wherein
adjusting delay in the positivity output signal and the negativity output signal so that the transfer device in the apparatus and the transfer device in the succeeding apparatus switch substantially at a same time to prompt a concurrent switching between the apparatus and the succeeding apparatus when the select control signal changes state.
13. The apparatus of claim 1 , wherein
the positivity output signal is coupled to the transfer device in the apparatus,
the negativity output signal is coupled to the enable output signal to enable the succeeding apparatus, and wherein
disposing a delay device to extend delay to the negativity output signal adapted to switch-off the transfer device in the apparatus before switch-on the transfer device of the succeeding apparatus prompts a break-before-make power multiplexing, when the select control signal changes from a logic high to a logic low level.
14. The apparatus of claim 1 , wherein
the positivity output signal is coupled to the transfer device in the apparatus,
the negativity output signal is coupled to the enable output signal to enable the succeeding apparatus, and wherein
disposing a delay device to extend delay to the positivity output signal adapted to switch-on the succeeding apparatus before switch-off the transfer device in the apparatus prompts a make-before-break power switching when the select control signal changes from a logic high to a logic low level.
15. The apparatus of claim 1 , wherein
the negativity output signal is coupled to the transfer device in the apparatus,
the positivity output signal is coupled to the enable output signal to enable the succeeding apparatus, and wherein
disposing a delay device to extend delay to the positivity output signal adapted to switch-off the transfer device in the apparatus before switch-on the succeeding apparatus prompts a break-before-make power multiplexing, when the select control signal changes from a logic low to a logic high level.
16. The apparatus of claim 1 , wherein
the negativity output signal is coupled to the transfer device in the apparatus,
the positivity output signal is coupled to the enable output signal to enable the succeeding apparatus, and wherein
disposing a delay device to extend delay to the negativity output signal adapted to switch-on the transfer device of the succeeding apparatus before switch-off the transfer device in the apparatus prompts a make-before-break power multiplexing, when the select control signal changes from a logic high to a logic low.
17. The apparatus of claim 1 , wherein the transfer section and the control section are formed in an integrated circuit.
18. The apparatus of claim 1 , wherein the transfer section is formed in a first integrated circuit and the control section is formed on a second integrated circuit.
19. The apparatus of claim 1 , wherein the apparatus is formed using discrete devices.
20. The apparatus of claim 1 , wherein apparatus is embedded in a power control system.
21. The apparatus of claim 1 , wherein
the energy device is coupled to the power output port and the comparator output is coupled to the charging control signal to generate the select control signal,
the negativity output signal is coupled to the transfer device in the transfer section, the positivity output signal is coupled to the enable output signal to the succeeding apparatus, and
when the enable input signal is asserted and the inhibit signal is negated, wherein
when the comparator input voltage derived from the energy device is below a predefined value, the comparator output saturates to a logic low value, the select control signal is negated:
negation of the select control signal (i) asserts the negativity output signal for the transfer device to enable a DC power source to charge the energy device coupled to the power output port, and (ii) negates the positivity output signal to negate the enable output signal to the succeeding apparatus; and
when the comparator input voltage derived from the energy device is above the predefined level, the comparator output saturates to a logic high value, the select control signal is asserted:
assertion of the select control signal (i) negates the negativity output signal for the transfer device to disconnect the DC power source from charging the energy device, and (ii) asserts the positivity output signal to enable the succeeding apparatus.
22. The apparatus of claim 1 , wherein
the select control signal is derived by an AND operation of the comparator output with the charging control signal and one or more signals representative of one or more abnormality conditions to control enable of the transfer device,
assertion of the signals representative of one or more abnormality conditions negates the transfer device in the apparatus and asserts the enable output signal to enable the succeeding apparatus.
23. The apparatus of claim 1 , wherein
the select control signal is derived by ANDing with one or more signals each representative of an abnormality condition comprising:
insufficient energy to the power input port,
over-voltage at the power input port,
over-temperature,
over-current,
short-circuit,
an external inhibit control signal to disable the transfer device,
wherein a detection of the one or more abnormality signals negates the transfer device in the apparatus and asserts the enable output signal to enable the second apparatus.
24. The apparatus of claim 1 , wherein
when the AND operation is converted to a NAND operation, the positivity output signal is converted to the negativity output signal and the negativity output signal is converted to the positivity output signal, and
when the NAND operation is converted into an OR operation, all inputs to the OR operation are inverted.
25. The apparatus of claim 1 , wherein a second enable input signal is ORed with the enable input signal to generate an ORed enable input signal to the demultiplexer.
26. The apparatus of claim 1 , wherein the energy device is a battery; wherein the transfer device transfers energy received from the power input port to the power output port to store energy in the battery during a charging operation.