1. An apparatus for use in an electrical power generation plant, said apparatus comprising:
at least two adjustable speed drives, each connected, on an alternating current side, to a respective auxiliary motor;
at least one reactive power consuming auxiliary device connected to an alternating current bus;
a single controller; and
a bus converter converting alternating current to direct current and vice versa between said alternating current bus and a direct current bus; and
at least two electrical power sources each coupled to said direct current bus through a respective converter, where both said at least two electrical power sources are configured to provide power to said direct current bus;
one of said at least two electrical power sources comprises a tertiary winding of a generator of said electrical power generation plant; and
each of said at least two adjustable speed drives is connected, on a direct current side, to said direct current bus;
wherein said controller is coupled to said at least two adjustable speed drives, to said at least one reactive power consuming auxiliary device, to at least one of the respective converters coupled to said at least two electrical power sources, and to said bus converter;
said controller controls the converter coupled to said generator based on a desired reactive power of the electrical power generation plant to reduce distribution of reactive power consumption over the electrical power generation plant.
2. The apparatus according to claim 1, wherein one of said at least two electrical power sources comprises a variable speed drive steam turbine generator.
3. The apparatus according to claim 2, wherein said controller is configured to control said variable speed drive steam turbine generator to thereby control a voltage of said direct current bus.
4. The apparatus according claim 1, wherein one of said at least two electrical power sources comprises a high inertia fan.
5. The apparatus according to claim 1, wherein one of said at least two electrical power sources comprises a start up source for said electrical power generation plant.
6. The apparatus according to claim 1, wherein one of said at least two electrical power sources generates electricity from rotating kinetic energy.
7. The apparatus according to claim 6, wherein one of said at least two electrical power sources generates electricity from rotating kinetic energy from a fan.
8. The apparatus according to claim 1, further comprising switchgears provided on said alternating current sides of each of said at least two adjustable speed drives.
9. The apparatus according to claim 1, wherein said apparatus comprises two direct current buses.
10. The apparatus according to claim 9, wherein each of said direct current buses is connected to a common alternating current bus.
11. The apparatus according to claim 1 further comprising sensors configured to measure reactive power where said sensor are connected to said controller, and where said controller controls said bus converter to control a level of the reactive power generated.
12. The apparatus according to claim 1, wherein said controller is configured to control one of said at least two electrical power sources to thereby control a voltage of said direct current bus.
13. The apparatus according to claim 12, wherein said controller is configured to control at least one electrical power source of a plurality of power sources to thereby control said voltage of said direct current bus.
14. The apparatus according to claim 1 wherein said controller is configured to control a voltage of the direct current bus.
15. The apparatus according to claim 1 wherein said controller is configured to control the direction of flow of electrical energy through said bus converter.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A direct current (DC)-DC controller, connected to an output stage and a load, wherein the output stage is connected to the load through an output inductor, the DC-DC controller comprising:
an error amplifier, having a first input terminal connected to one terminal of the output inductor, and a second input terminal receives a reference voltage;
a pulse width modulation (PWM) generation circuit, connected to the error amplifier, and providing a PWM signal to the output stage; and
a compensation circuit, connected to an output terminal of the error amplifier, and comprising an adjustable capacitor circuit, wherein the adjustable capacitor circuit dynamically adjusts an equivalent capacitance value according to a change of the load.
2. The DC-DC controller as claimed in claim 1, wherein the adjustable capacitor circuit downgrades the equivalent capacitance value in case of a transient change of the load.
3. The DC-DC controller as claimed in claim 1, wherein the adjustable capacitor circuit comprises:
a capacitance amplifying circuit, providing the equivalent capacitance value; and
a current detecting circuit, connected to the output terminal of the error amplifier and the capacitance amplifying circuit, and dynamically controlling the capacitance amplifying circuit according to the change of the load.
4. The DC-DC controller as claimed in claim 3, wherein the capacitance amplifying circuit comprises:
a first amplifier;
a first resistor, connected to a first input terminal of the first amplifier;
a second resistor, having a first terminal connected to the first resistor, and a second terminal connected to a second input terminal of the first amplifier;
a first capacitor, coupled between the first input terminal of the first amplifier and a ground terminal;
a first controllable current source, having a first terminal connected to an operating voltage, a control terminal connected to the current detecting circuit, a second terminal connected to the second terminal of the second resistor and the second input terminal of the first amplifier, and a third terminal connected to the first amplifier; and
a second controllable current source, having a first terminal connected to the second terminal of the first controllable current source, the second terminal of the second resistor and the second input terminal of the first amplifier, a control terminal connected to the current detecting circuit, and a second terminal connected to the ground terminal.
5. The DC-DC controller as claimed in claim 1, wherein the adjustable capacitor circuit comprises:
a capacitance amplifying circuit, providing the equivalent capacitance value; and
a voltage detecting circuit, connected to the first input terminal and the second input terminal of the error amplifier and the capacitance amplifying circuit, and dynamically controlling the capacitance amplifying circuit according to the change of the load.
6. The DC-DC controller as claimed in claim 5, wherein the voltage detecting circuit comprises a second amplifier, a first input terminal of the second amplifier is connected to the second input terminal of the error amplifier, a second input terminal of the second amplifier is connected to the first input terminal of the error amplifier, and an output terminal of the second amplifier is connected to the capacitance amplifying circuit.
7. The DC-DC controller as claimed in claim 5, wherein the capacitance amplifying circuit comprises:
a first amplifier;
a first resistor, connected to a first input terminal of the first amplifier;
a second resistor, having a first terminal connected to the first resistor, and a second terminal connected to a second input terminal of the first amplifier;
a first capacitor, coupled between the first input terminal of the first amplifier and a ground terminal;
a first controllable current source, having a first terminal connected to an operating voltage, a control terminal connected to the voltage detecting circuit, a second terminal connected to the second terminal of the second resistor and the second input terminal of the first amplifier, and a third terminal connected to the first amplifier; and
a second controllable current source, having a first terminal connected to the second terminal of the first controllable current source, the second terminal of the second resistor and the second input terminal of the first amplifier, a control terminal connected to the voltage detecting circuit, and a second terminal connected to the ground terminal.
8. The DC-DC controller as claimed in claim 1, wherein the adjustable capacitor circuit comprises:
a capacitance amplifying circuit, providing the equivalent capacitance value; and
a surge detecting circuit, connected to the second input terminal or the output terminal of the error amplifier, and dynamically controlling the capacitance amplifying circuit according to the change of the load.
9. The DC-DC controller as claimed in claim 8, wherein the surge detecting circuit comprises a differentiator.
10. The DC-DC controller as claimed in claim 8, wherein the capacitance amplifying circuit comprises:
a first amplifier;
a first resistor, connected to a first input terminal of the first amplifier;
a second resistor, having a first terminal connected to the first resistor, and a second terminal connected to a second input terminal of the first amplifier;
a first capacitor, coupled between the first input terminal of the first amplifier and a ground terminal;
a first controllable current source, having a first terminal connected to an operating voltage, a control terminal connected to the surge detecting circuit, a second terminal connected to the second terminal of the second resistor and the second input terminal of the first amplifier, and a third terminal connected to the first amplifier; and
a second controllable current source, having a first terminal connected to the second terminal of the first controllable current source, the second terminal of the second resistor and the second input terminal of the first amplifier, a control terminal connected to the surge detecting circuit, and a second terminal connected to the ground terminal.